diff --git a/Business/Finance/FinanceFormulas.php b/Business/Finance/FinanceFormulas.php
index 26e88cc3c..169b2cc74 100644
--- a/Business/Finance/FinanceFormulas.php
+++ b/Business/Finance/FinanceFormulas.php
@@ -1063,7 +1063,7 @@ class FinanceFormulas
 
         $npv = -$C[0];
 
-        for ($i = 1; $i < $count; $i++) {
+        for ($i = 1; $i < $count; ++$i) {
             $npv += $C[$i] / pow(1 + $r, $i);
         }
 
diff --git a/Business/Finance/Forecasting/ARIMA.php b/Business/Finance/Forecasting/ARIMA.php
index 00de6c245..8eb077cfe 100644
--- a/Business/Finance/Forecasting/ARIMA.php
+++ b/Business/Finance/Forecasting/ARIMA.php
@@ -77,7 +77,7 @@ class ARIMA
         $remainder = [];
         $count     = count($prelimSeasonalComponent);
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             // +1 since 3x3 MA
             $remainder[] = $centeredRatios[$i + 1] / $prelimSeasonalComponent[$i];
         }
@@ -103,7 +103,7 @@ class ARIMA
         $centeredRatio = [];
         $count         = count($seasonal);
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             // +1 since 3x3 MA
             $centeredRatio[] = $remainder[$i + 1] * $seasonal[$i];
         }
@@ -134,7 +134,7 @@ class ARIMA
         $count    = count($seasonal);
         $start    = ClassicalDecomposition::getStartOfDecomposition(count($this->data), $count);
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $adjusted[] = $this->data[$start + $i] / $seasonal[$i];
         }
 
@@ -156,7 +156,7 @@ class ARIMA
         $data  = [];
         $count = count($trendCycleComponent);
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $data[] = $trendCycleComponent[$i] * $seasonalAdjustedSeries[$i] * $remainder[$i];
         }
 
diff --git a/Business/Finance/Forecasting/ClassicalDecomposition.php b/Business/Finance/Forecasting/ClassicalDecomposition.php
index 8a75a43f2..97db1918b 100644
--- a/Business/Finance/Forecasting/ClassicalDecomposition.php
+++ b/Business/Finance/Forecasting/ClassicalDecomposition.php
@@ -151,7 +151,7 @@ class ClassicalDecomposition
         $count     = count($trendCycleComponent);
         $start     = self::getStartOfDecomposition(count($data), $count);
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $detrended[] = $mode === self::ADDITIVE ? $data[$start + $i] - $trendCycleComponent[$i] : $data[$start + $i] / $trendCycleComponent[$i];
         }
 
@@ -192,7 +192,7 @@ class ClassicalDecomposition
         $seasonalComponent = [];
         $count             = count($detrendedSeries);
 
-        for ($i = 0; $i < $order; $i++) {
+        for ($i = 0; $i < $order; ++$i) {
             $temp = [];
 
             for ($j = $i; $j < $count; $j += $order) {
@@ -225,7 +225,7 @@ class ClassicalDecomposition
         $start              = self::getStartOfDecomposition($dataSize, $count);
         $seasons            = count($seasonalComponent);
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $remainderComponent[] = $mode === self::ADDITIVE ? $data[$start + $i] - $trendCycleComponent[$i] - $seasonalComponent[$i % $seasons] : $data[$start + $i] / ($trendCycleComponent[$i] * $seasonalComponent[$i % $seasons]);
         }
 
diff --git a/Business/Sales/MarketShareEstimation.php b/Business/Sales/MarketShareEstimation.php
index 6acf18dcf..324fa8ae0 100644
--- a/Business/Sales/MarketShareEstimation.php
+++ b/Business/Sales/MarketShareEstimation.php
@@ -43,7 +43,7 @@ class MarketShareEstimation
     public static function getRankFromMarketShare(int $participants, float $marketShare, float $modifier = 1.0) : int
     {
         $sum = 0.0;
-        for ($i = 0; $i < $participants; $i++) {
+        for ($i = 0; $i < $participants; ++$i) {
             $sum += 1 / pow($i + 1, $modifier);
         }
 
@@ -66,7 +66,7 @@ class MarketShareEstimation
     public static function getMarketShareFromRank(int $participants, int $rank, float $modifier = 1.0) : float
     {
         $sum = 0.0;
-        for ($i = 0; $i < $participants; $i++) {
+        for ($i = 0; $i < $participants; ++$i) {
             $sum += 1 / pow($i + 1, $modifier);
         }
 
diff --git a/Math/Functions/Fibunacci.php b/Math/Functions/Fibunacci.php
index 068ddd060..5282a9e37 100644
--- a/Math/Functions/Fibunacci.php
+++ b/Math/Functions/Fibunacci.php
@@ -61,7 +61,7 @@ class Fibunacci
         $old2 = $start;
         $fib  = 0;
 
-        for ($i = 2; $i < $n; $i++) {
+        for ($i = 2; $i < $n; ++$i) {
             $fib  = $old1 + $old2;
             $old1 = $old2;
             $old2 = $fib;
diff --git a/Math/Functions/Functions.php b/Math/Functions/Functions.php
index 0ae2d8970..91dfdf330 100644
--- a/Math/Functions/Functions.php
+++ b/Math/Functions/Functions.php
@@ -56,7 +56,7 @@ class Functions
     {
         $fact = 1;
 
-        for ($i = $start; $i < $n + 1; $i++) {
+        for ($i = $start; $i < $n + 1; ++$i) {
             $fact *= $i;
         }
 
@@ -85,7 +85,7 @@ class Functions
         $fact  = 1;
         $range = array_reverse(range(1, $min));
 
-        for ($i = $max + 1; $i < $n + 1; $i++) {
+        for ($i = $max + 1; $i < $n + 1; ++$i) {
             $div = 1;
             foreach ($range as $key => $d) {
                 if ($i % $d === 0) {
diff --git a/Math/Geometry/Shape/D2/Polygon.php b/Math/Geometry/Shape/D2/Polygon.php
index aaa3696bc..64aaaa33f 100644
--- a/Math/Geometry/Shape/D2/Polygon.php
+++ b/Math/Geometry/Shape/D2/Polygon.php
@@ -103,7 +103,7 @@ class Polygon implements D2ShapeInterface
         $polygonCount   = count($polygon);
 
         // todo: return based on highest possibility not by first match
-        for ($i = 1; $i < $polygonCount; $i++) {
+        for ($i = 1; $i < $polygonCount; ++$i) {
             $vertex1 = $polygon[$i - 1];
             $vertex2 = $polygon[$i];
 
@@ -200,7 +200,7 @@ class Polygon implements D2ShapeInterface
         $count   = count($this->coord);
         $surface = 0;
 
-        for ($i = 0; $i < $count - 1; $i++) {
+        for ($i = 0; $i < $count - 1; ++$i) {
             $surface += $this->coord[$i]['x'] * $this->coord[$i + 1]['y'] - $this->coord[$i + 1]['x'] * $this->coord[$i]['y'];
         }
 
@@ -222,7 +222,7 @@ class Polygon implements D2ShapeInterface
         $count     = count($this->coord);
         $perimeter = sqrt(($this->coord[0]['x'] - $this->coord[$count - 1]['x']) ** 2 + ($this->coord[0]['y'] - $this->coord[$count - 1]['y']) ** 2);
 
-        for ($i = 0; $i < $count - 1; $i++) {
+        for ($i = 0; $i < $count - 1; ++$i) {
             $perimeter += sqrt(($this->coord[$i + 1]['x'] - $this->coord[$i]['x']) ** 2 + ($this->coord[$i + 1]['y'] - $this->coord[$i]['y']) ** 2);
         }
 
@@ -241,7 +241,7 @@ class Polygon implements D2ShapeInterface
         $barycenter = ['x' => 0, 'y' => 0];
         $count      = count($this->coord);
 
-        for ($i = 0; $i < $count - 1; $i++) {
+        for ($i = 0; $i < $count - 1; ++$i) {
             $mult             = ($this->coord[$i]['x'] * $this->coord[$i + 1]['y'] - $this->coord[$i + 1]['x'] * $this->coord[$i]['y']);
             $barycenter['x'] += ($this->coord[$i]['x'] + $this->coord[$i + 1]['x']) * $mult;
             $barycenter['y'] += ($this->coord[$i]['y'] + $this->coord[$i + 1]['y']) * $mult;
diff --git a/Math/Matrix/CholeskyDecomposition.php b/Math/Matrix/CholeskyDecomposition.php
index 27cea1958..867906104 100644
--- a/Math/Matrix/CholeskyDecomposition.php
+++ b/Math/Matrix/CholeskyDecomposition.php
@@ -83,9 +83,9 @@ class CholeskyDecomposition
         $n = $B->getN();
 
         // Solve L*Y = B;
-        for ($k = 0; $k < $this->m; $k++) {
-            for ($j = 0; $j < $n; $j++) {
-                for ($i = 0; $i < $k; $i++) {
+        for ($k = 0; $k < $this->m; ++$k) {
+            for ($j = 0; $j < $n; ++$j) {
+                for ($i = 0; $i < $k; ++$i) {
                     $X[$k][$j] -= $X[$i][$j] * $this->L[$k][$i];
                 }
 
@@ -95,8 +95,8 @@ class CholeskyDecomposition
 
         // Solve L'*X = Y;
         for ($k = $this->m - 1; $k >= 0; $k--) {
-            for ($j = 0; $j < $n; $j++) {
-                for ($i = $k + 1; $i < $this->m; $i++) {
+            for ($j = 0; $j < $n; ++$j) {
+                for ($i = $k + 1; $i < $this->m; ++$i) {
                     $X[$k][$j] -= $X[$i][$j] * $this->L[$i][$k];
                 }
 
diff --git a/Math/Matrix/IdentityMatrix.php b/Math/Matrix/IdentityMatrix.php
index 94b557a1e..875155b34 100644
--- a/Math/Matrix/IdentityMatrix.php
+++ b/Math/Matrix/IdentityMatrix.php
@@ -35,7 +35,7 @@ class IdentityMatrix extends Matrix
     {
         parent::__construct($n, $n);
 
-        for ($i = 0; $i < $n; $i++) {
+        for ($i = 0; $i < $n; ++$i) {
             $this->matrix[$i][$i] = 1;
         }
     }
diff --git a/Math/Matrix/Matrix.php b/Math/Matrix/Matrix.php
index c680ace61..1fb6d1ba4 100644
--- a/Math/Matrix/Matrix.php
+++ b/Math/Matrix/Matrix.php
@@ -71,7 +71,7 @@ class Matrix implements \ArrayAccess, \Iterator
         $this->n = $n;
         $this->m = $m;
 
-        for ($i = 0; $i < $m; $i++) {
+        for ($i = 0; $i < $m; ++$i) {
             $this->matrix[$i] = array_fill(0, $n, 0);
         }
     }
@@ -361,11 +361,11 @@ class Matrix implements \ArrayAccess, \Iterator
         $newMatrix    = new Matrix($this->m, $nDim);
         $newMatrixArr = $newMatrix->getMatrix();
 
-        for ($i = 0; $i < $this->m; $i++) { // Row of $this
-            for ($c = 0; $c < $nDim; $c++) { // Column of $matrix
+        for ($i = 0; $i < $this->m; ++$i) { // Row of $this
+            for ($c = 0; $c < $nDim; ++$c) { // Column of $matrix
                 $temp = 0;
 
-                for ($j = 0; $j < $mDim; $j++) { // Row of $matrix
+                for ($j = 0; $j < $mDim; ++$j) { // Row of $matrix
                     $temp += $this->matrix[$i][$j] * $matrixArr[$j][$c];
                 }
 
@@ -437,10 +437,10 @@ class Matrix implements \ArrayAccess, \Iterator
         $n    = count($arr);
         $sign = 1;
 
-        for ($i = 0; $i < $n; $i++) {
+        for ($i = 0; $i < $n; ++$i) {
             $max = 0;
 
-            for ($j = $i; $j < $n; $j++) {
+            for ($j = $i; $j < $n; ++$j) {
                 if (abs($arr[$j][$i]) > abs($arr[$max][$i])) {
                     $max = $j;
                 }
@@ -457,14 +457,14 @@ class Matrix implements \ArrayAccess, \Iterator
                 return 0;
             }
 
-            for ($j = $i + 1; $j < $n; $j++) {
+            for ($j = $i + 1; $j < $n; ++$j) {
                 $r = $arr[$j][$i] / $arr[$i][$i];
 
                 if (!$r) {
                     continue;
                 }
 
-                for ($c = $i; $c < $n; $c++) {
+                for ($c = $i; $c < $n; ++$c) {
                     $arr[$j][$c] -= $arr[$i][$c] * $r;
                 }
             }
@@ -514,8 +514,8 @@ class Matrix implements \ArrayAccess, \Iterator
         $newMatrixArr = $this->matrix;
 
         // extending matrix by identity matrix
-        for ($i = 0; $i < $this->n; $i++) {
-            for ($j = $this->n; $j < $this->n * 2; $j++) {
+        for ($i = 0; $i < $this->n; ++$i) {
+            for ($j = $this->n; $j < $this->n * 2; ++$j) {
 
                 if ($j === ($i + $this->n)) {
                     $newMatrixArr[$i][$j] = 1;
@@ -532,16 +532,16 @@ class Matrix implements \ArrayAccess, \Iterator
         $newMatrixArr = $this->diag($newMatrixArr);
 
         /* create unit matrix */
-        for ($i = 0; $i < $mDim; $i++) {
+        for ($i = 0; $i < $mDim; ++$i) {
             $temp = $newMatrixArr[$i][$i];
 
-            for ($j = 0; $j < $nDim; $j++) {
+            for ($j = 0; $j < $nDim; ++$j) {
                 $newMatrixArr[$i][$j] = $newMatrixArr[$i][$j] / $temp;
             }
         }
 
         /* removing identity matrix */
-        for ($i = 0; $i < $mDim; $i++) {
+        for ($i = 0; $i < $mDim; ++$i) {
             $newMatrixArr[$i] = array_slice($newMatrixArr[$i], $mDim);
         }
 
@@ -575,7 +575,7 @@ class Matrix implements \ArrayAccess, \Iterator
             $j   = $col;
             $max = $matrix[$j][$j];
 
-            for ($i = $col + 1; $i < $mDim; $i++) {
+            for ($i = $col + 1; $i < $mDim; ++$i) {
                 $temp = abs($matrix[$i][$col]);
 
                 if ($temp > $max) {
@@ -594,10 +594,10 @@ class Matrix implements \ArrayAccess, \Iterator
                 $b[$j]   = $temp;
             }
 
-            for ($i = $col + 1; $i < $mDim; $i++) {
+            for ($i = $col + 1; $i < $mDim; ++$i) {
                 $temp = $matrix[$i][$col] / $matrix[$col][$col];
 
-                for ($j = $col + 1; $j < $mDim; $j++) {
+                for ($j = $col + 1; $j < $mDim; ++$j) {
                     $matrix[$i][$j] -= $temp * $matrix[$col][$j];
                 }
 
@@ -638,7 +638,7 @@ class Matrix implements \ArrayAccess, \Iterator
 
         for ($i = $mDim - 1; $i > 0; $i--) {
             if ($arr[$i - 1][0] < $arr[$i][0]) {
-                for ($j = 0; $j < $nDim; $j++) {
+                for ($j = 0; $j < $nDim; ++$j) {
                     $temp            = $arr[$i][$j];
                     $arr[$i][$j]     = $arr[$i - 1][$j];
                     $arr[$i - 1][$j] = $temp;
@@ -647,12 +647,12 @@ class Matrix implements \ArrayAccess, \Iterator
         }
 
         /* create diagonal matrix */
-        for ($i = 0; $i < $mDim; $i++) {
-            for ($j = 0; $j < $mDim; $j++) {
+        for ($i = 0; $i < $mDim; ++$i) {
+            for ($j = 0; $j < $mDim; ++$j) {
                 if ($j !== $i) {
                     $temp = $arr[$j][$i] / $arr[$i][$i];
 
-                    for ($c = 0; $c < $nDim; $c++) {
+                    for ($c = 0; $c < $nDim; ++$c) {
                         $arr[$j][$c] -= $arr[$i][$c] * $temp;
                     }
                 }
diff --git a/Math/Number/Integer.php b/Math/Number/Integer.php
index 1e0eb57b1..47d33c7b4 100644
--- a/Math/Number/Integer.php
+++ b/Math/Number/Integer.php
@@ -92,7 +92,7 @@ class Integer
     public static function pollardsRho(int $n, int $x = 2, int $factor = 1, int $cycleSize = 2, int $y = 2) : int
     {
         while ($factor === 1) {
-            for ($i = 1; $i < $cycleSize && $factor <= 1; $i++) {
+            for ($i = 1; $i < $cycleSize && $factor <= 1; ++$i) {
                 $x      = ($x * $x + 1) % $n;
                 $factor = self::greatestCommonDivisor($x - $y, $n);
             }
diff --git a/Math/Number/Numbers.php b/Math/Number/Numbers.php
index ea8bdfc1b..bfb1fade2 100644
--- a/Math/Number/Numbers.php
+++ b/Math/Number/Numbers.php
@@ -37,7 +37,7 @@ class Numbers
     {
         $sum = 0;
 
-        for ($i = 1; $i < $n; $i++) {
+        for ($i = 1; $i < $n; ++$i) {
             if ($n % $i == 0) {
                 $sum += $i;
             }
diff --git a/Math/Number/Prime.php b/Math/Number/Prime.php
index a138aaef7..4e54e3f60 100644
--- a/Math/Number/Prime.php
+++ b/Math/Number/Prime.php
@@ -82,7 +82,7 @@ class Prime
             $s++;
         }
 
-        for ($i = 0; $i < $k; $i++) {
+        for ($i = 0; $i < $k; ++$i) {
             $a = mt_rand(2, $n - 1);
 
             $x = bcpowmod((string) $a, (string) $d, (string) $n);
@@ -91,7 +91,7 @@ class Prime
                 continue;
             }
 
-            for ($j = 1; $j < $s; $j++) {
+            for ($j = 1; $j < $s; ++$j) {
                 $x = bcmod(bcmul($x, $x), (string) $n);
 
                 if ($x == 1) {
diff --git a/Math/Optimization/TSP/BruteForce.php b/Math/Optimization/TSP/BruteForce.php
index b5ad1c488..f4ece4ecf 100644
--- a/Math/Optimization/TSP/BruteForce.php
+++ b/Math/Optimization/TSP/BruteForce.php
@@ -95,7 +95,7 @@ class BruteForce
         }
 
         $count = count($cities);
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $extended = clone $tour;
             $extended->addCity($cities[$i]);
             unset($cities[$i]);
diff --git a/Math/Optimization/TSP/GA.php b/Math/Optimization/TSP/GA.php
index d88668406..686890fab 100644
--- a/Math/Optimization/TSP/GA.php
+++ b/Math/Optimization/TSP/GA.php
@@ -84,7 +84,7 @@ class GA
 
         $newPopulation->add($population->getFittest());
 
-        for ($i = $shift; $i < $count; $i++) {
+        for ($i = $shift; $i < $count; ++$i) {
             $parent1 = $this->tournamentSelection($population);
             $parent2 = $this->tournamentSelection($population);
             $child   = $this->crossover($parent1, $parent2);
@@ -94,7 +94,7 @@ class GA
 
         $count2 = $newPopulation->count();
 
-        for ($i = $shift; $i < $count2; $i++) {
+        for ($i = $shift; $i < $count2; ++$i) {
             $this->mutate($newPopulation->get($i));
         }
 
@@ -115,7 +115,7 @@ class GA
         $tournament     = new Population($this->cityPool, self::TOURNAMENT, false);
         $populationSize = $population->count() - 1;
 
-        for ($i = 0; $i < self::TOURNAMENT; $i++) {
+        for ($i = 0; $i < self::TOURNAMENT; ++$i) {
             $tournament->add($population->get(mt_rand(0, $populationSize)));
         }
 
@@ -141,7 +141,7 @@ class GA
 
         $count = $child->count(); /* $tour1->count() ???!!!! */
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             if ($start < $end && $i > $start && $i < $end) {
                 $child->setCity($i, $tour1->getCity($i));
             } elseif ($start > $end && !($i < $start && $i > $end)) {
@@ -151,9 +151,9 @@ class GA
 
         $count = $tour2->count();
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             if (!$child->hasCity($tour2->getCity($i))) {
-                for ($j = 0; $j < $child->count(); $j++) {
+                for ($j = 0; $j < $child->count(); ++$j) {
                     if ($child->getCity($j) === null) {
                         $child->setCity($j, $tour2->getCity($i));
                         break;
diff --git a/Math/Optimization/TSP/Population.php b/Math/Optimization/TSP/Population.php
index bfec067ff..725537d19 100644
--- a/Math/Optimization/TSP/Population.php
+++ b/Math/Optimization/TSP/Population.php
@@ -44,7 +44,7 @@ class Population implements \Countable
     public function __construct(CityPool $pool, int $size, bool $initialize = false)
     {
         if ($initialize) {
-            for ($i = 0; $i < $size; $i++) {
+            for ($i = 0; $i < $size; ++$i) {
                 $this->tours[] = new Tour($pool, true);
             }
         }
@@ -115,7 +115,7 @@ class Population implements \Countable
         $fittest = $this->tours[0];
         $count   = count($this->tours);
 
-        for ($i = 1; $i < $count; $i++) {
+        for ($i = 1; $i < $count; ++$i) {
             if ($fittest->getFitness() <= $this->tours[$i]->getFitness()) {
                 $fittest = $this->tours[$i];
             }
@@ -136,7 +136,7 @@ class Population implements \Countable
         $unfittest = $this->tours[0];
         $count     = count($this->tours);
 
-        for ($i = 1; $i < $count; $i++) {
+        for ($i = 1; $i < $count; ++$i) {
             if ($unfittest->getFitness() >= $this->tours[$i]->getFitness()) {
                 $unfittest = $this->tours[$i];
             }
diff --git a/Math/Optimization/TSP/Tour.php b/Math/Optimization/TSP/Tour.php
index c5d3ac5a0..53f010a7b 100644
--- a/Math/Optimization/TSP/Tour.php
+++ b/Math/Optimization/TSP/Tour.php
@@ -118,7 +118,7 @@ class Tour implements \Countable
 
             $count = count($this->cities);
 
-            for ($i = 0; $i < $count; $i++) {
+            for ($i = 0; $i < $count; ++$i) {
                 $dest = ($i + 1 < $count) ? $this->cities[$i + 1] : $this->cities[0];
 
                 $distance += $this->cities[$i]->getDistanceTo($dest);
diff --git a/Math/Statistic/Average.php b/Math/Statistic/Average.php
index 12efba65d..0b87a6bf2 100644
--- a/Math/Statistic/Average.php
+++ b/Math/Statistic/Average.php
@@ -77,7 +77,7 @@ class Average
         $count   = count($x) - ($symmetric ? $periods : 0);
         $avg     = [];
 
-        for ($i = $periods; $i < $count; $i++) {
+        for ($i = $periods; $i < $count; ++$i) {
             $avg[] = self::movingAverage($x, $i, $order, $weight, $symmetric);
         }
 
@@ -141,7 +141,7 @@ class Average
 
         $avg = 0.0;
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $avg += $values[$i] * $weight[$i];
         }
 
@@ -294,10 +294,11 @@ class Average
      */
     public static function angleMean($angles, int $offset = 0) : float
     {
-        $y    = $x = 0;
+        $y    = 0;
+        $x    = 0;
         $size = count($angles);
 
-        for ($i = 0; $i < $size; $i++) {
+        for ($i = 0; $i < $size; ++$i) {
             $x += cos(deg2rad($angles[$i]));
             $y += sin(deg2rad($angles[$i]));
         }
diff --git a/Math/Statistic/Correlation.php b/Math/Statistic/Correlation.php
index 041d73ac4..d9cdf3e7b 100644
--- a/Math/Statistic/Correlation.php
+++ b/Math/Statistic/Correlation.php
@@ -59,7 +59,7 @@ class Correlation
         $count                = count($x);
         $sum                  = 0.0;
 
-        for ($i = $k + 1; $i < $count; $i++) {
+        for ($i = $k + 1; $i < $count; ++$i) {
             $sum += ($x[$i] - $mean) * ($x[$i - $k] - $mean);
         }
 
@@ -79,7 +79,7 @@ class Correlation
     public static function boxPierceTest(array $autocorrelations, int $h) : float
     {
         $sum = 0;
-        for ($i = 0; $i < $h; $i++) {
+        for ($i = 0; $i < $h; ++$i) {
             $sum += $autocorrelations[$i] ** 2;
         }
 
@@ -101,7 +101,7 @@ class Correlation
         $count = count($autocorrelations);
         $sum   = 0;
 
-        for ($i = 0; $i < $h; $i++) {
+        for ($i = 0; $i < $h; ++$i) {
             $sum += 1 / ($count - $i) * $autocorrelations[$i] ** 2;
         }
 
diff --git a/Math/Statistic/Forecast/Error.php b/Math/Statistic/Forecast/Error.php
index 4f8589ebb..eb3e543b5 100644
--- a/Math/Statistic/Forecast/Error.php
+++ b/Math/Statistic/Forecast/Error.php
@@ -164,11 +164,11 @@ class Error
         $sum2   = 0;
         $meanY  = Average::arithmeticMean($observed);
 
-        for ($i = 0; $i < $countF; $i++) {
+        for ($i = 0; $i < $countF; ++$i) {
             $sum1 += ($forecasted[$i] - $meanY) ** 2;
         }
 
-        for ($i = 0; $i < $countO; $i++) {
+        for ($i = 0; $i < $countO; ++$i) {
             $sum2 += ($observed[$i] - $meanY) ** 2;
         }
 
@@ -444,7 +444,7 @@ class Error
         $sum   = 0.0;
         $count = count($observed);
 
-        for ($i = 0 + $m; $i < $count; $i++) {
+        for ($i = 0 + $m; $i < $count; ++$i) {
             $sum += abs($observed[$i] - $observed[$i - $m]);
         }
 
diff --git a/Math/Statistic/Forecast/Regression/LevelLogRegression.php b/Math/Statistic/Forecast/Regression/LevelLogRegression.php
index 969553006..1394022bf 100644
--- a/Math/Statistic/Forecast/Regression/LevelLogRegression.php
+++ b/Math/Statistic/Forecast/Regression/LevelLogRegression.php
@@ -35,7 +35,7 @@ class LevelLogRegression extends RegressionAbstract
             throw new InvalidDimensionException($c . 'x' . count($y));
         }
 
-        for ($i = 0; $i < $c; $i++) {
+        for ($i = 0; $i < $c; ++$i) {
             $x[$i] = log($x[$i]);
         }
 
diff --git a/Math/Statistic/Forecast/Regression/LogLevelRegression.php b/Math/Statistic/Forecast/Regression/LogLevelRegression.php
index eebd46c4b..30b92e24f 100644
--- a/Math/Statistic/Forecast/Regression/LogLevelRegression.php
+++ b/Math/Statistic/Forecast/Regression/LogLevelRegression.php
@@ -35,7 +35,7 @@ class LogLevelRegression extends RegressionAbstract
             throw new InvalidDimensionException($c . 'x' . count($y));
         }
 
-        for ($i = 0; $i < $c; $i++) {
+        for ($i = 0; $i < $c; ++$i) {
             $y[$i] = log($y[$i]);
         }
 
diff --git a/Math/Statistic/Forecast/Regression/LogLogRegression.php b/Math/Statistic/Forecast/Regression/LogLogRegression.php
index 240abf9cb..fdc4b303f 100644
--- a/Math/Statistic/Forecast/Regression/LogLogRegression.php
+++ b/Math/Statistic/Forecast/Regression/LogLogRegression.php
@@ -35,7 +35,7 @@ class LogLogRegression extends RegressionAbstract
             throw new InvalidDimensionException($c . 'x' . count($y));
         }
 
-        for ($i = 0; $i < $c; $i++) {
+        for ($i = 0; $i < $c; ++$i) {
             $x[$i] = log($x[$i]);
             $y[$i] = log($y[$i]);
         }
diff --git a/Math/Statistic/Forecast/Regression/RegressionAbstract.php b/Math/Statistic/Forecast/Regression/RegressionAbstract.php
index 9462f3784..19be45a92 100644
--- a/Math/Statistic/Forecast/Regression/RegressionAbstract.php
+++ b/Math/Statistic/Forecast/Regression/RegressionAbstract.php
@@ -71,7 +71,7 @@ abstract class RegressionAbstract
         $count = count($errors);
         $sum   = 0.0;
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $sum += $errors[$i] ** 2;
         }
 
@@ -97,7 +97,7 @@ abstract class RegressionAbstract
         $meanX = Average::arithmeticMean($x);
         $sum   = 0.0;
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $sum += ($x[$i] - $meanX) ** 2;
         }
 
@@ -127,7 +127,7 @@ abstract class RegressionAbstract
         $sum1 = 0;
         $sum2 = 0;
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $sum1 += ($y[$i] - $meanY) * ($x[$i] - $meanX);
             $sum2 += ($x[$i] - $meanX) ** 2;
         }
diff --git a/Math/Statistic/MeasureOfDispersion.php b/Math/Statistic/MeasureOfDispersion.php
index 48d3584d7..3dd06c17b 100644
--- a/Math/Statistic/MeasureOfDispersion.php
+++ b/Math/Statistic/MeasureOfDispersion.php
@@ -174,7 +174,7 @@ class MeasureOfDispersion
 
         $sum = 0.0;
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $sum += ($x[$i] - $xMean) * ($y[$i] - $yMean);
         }
 
diff --git a/Math/Stochastic/Distribution/BinomialDistribution.php b/Math/Stochastic/Distribution/BinomialDistribution.php
index aa2c8d980..1cb68bb11 100644
--- a/Math/Stochastic/Distribution/BinomialDistribution.php
+++ b/Math/Stochastic/Distribution/BinomialDistribution.php
@@ -128,7 +128,7 @@ class BinomialDistribution
     {
         $sum = 0.0;
 
-        for ($i = 0; $i < $x; $i++) {
+        for ($i = 0; $i < $x; ++$i) {
             $sum += self::getPmf($n, $i, $p);
         }
 
diff --git a/Math/Stochastic/Distribution/ChiSquaredDistribution.php b/Math/Stochastic/Distribution/ChiSquaredDistribution.php
index a970c10cd..228948346 100644
--- a/Math/Stochastic/Distribution/ChiSquaredDistribution.php
+++ b/Math/Stochastic/Distribution/ChiSquaredDistribution.php
@@ -95,7 +95,7 @@ class ChiSquaredDistribution
 
         $sum = 0.0;
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $sum += ($dataset[$i] - $expected[$i]) * ($dataset[$i] - $expected[$i]) / $expected[$i];
         }
 
diff --git a/Math/Stochastic/Distribution/PoissonDistribution.php b/Math/Stochastic/Distribution/PoissonDistribution.php
index fa40d2c69..b14d712ba 100644
--- a/Math/Stochastic/Distribution/PoissonDistribution.php
+++ b/Math/Stochastic/Distribution/PoissonDistribution.php
@@ -57,7 +57,7 @@ class PoissonDistribution
     {
         $sum = 0.0;
 
-        for ($i = 0; $i < $k + 1; $i++) {
+        for ($i = 0; $i < $k + 1; ++$i) {
             $sum += pow($lambda, $i) / Functions::fact($i);
         }
 
diff --git a/Message/Http/Request.php b/Message/Http/Request.php
index a0c18c21b..52de748ec 100644
--- a/Message/Http/Request.php
+++ b/Message/Http/Request.php
@@ -231,7 +231,7 @@ class Request extends RequestAbstract
 
         foreach ($pathArray as $key => $path) {
             $paths = [];
-            for ($i = $start; $i < $key + 1; $i++) {
+            for ($i = $start; $i < $key + 1; ++$i) {
                 $paths[] = $pathArray[$i];
             }
 
diff --git a/Module/ModuleManager.php b/Module/ModuleManager.php
index 3cca21cda..206b3a532 100644
--- a/Module/ModuleManager.php
+++ b/Module/ModuleManager.php
@@ -149,9 +149,9 @@ class ModuleManager
                     $i = 1;
                     $c = count($uriHash);
 
-                    for ($k = 0; $k < $c; $k++) {
+                    for ($k = 0; $k < $c; ++$k) {
                         $uriPdo .= ':pid' . $i . ',';
-                        $i++;
+                        ++$i;
                     }
 
                     $uriPdo = rtrim($uriPdo, ',');
@@ -169,7 +169,7 @@ class ModuleManager
                     $i = 1;
                     foreach ($uriHash as $hash) {
                         $sth->bindValue(':pid' . $i, $hash, \PDO::PARAM_STR);
-                        $i++;
+                        ++$i;
                     }
 
                     $sth->execute();
@@ -229,7 +229,7 @@ class ModuleManager
             $files = glob('*', GLOB_ONLYDIR);
             $c     = count($files);
 
-            for ($i = 0; $i < $c; $i++) {
+            for ($i = 0; $i < $c; ++$i) {
                 $path = $this->modulePath . '/' . $files[$i] . '/info.json';
 
                 if (!file_exists($path)) {
diff --git a/Stdlib/Base/SmartDateTime.php b/Stdlib/Base/SmartDateTime.php
index 755f0179d..1474657e0 100644
--- a/Stdlib/Base/SmartDateTime.php
+++ b/Stdlib/Base/SmartDateTime.php
@@ -260,13 +260,13 @@ class SmartDateTime extends \DateTime
         $daysPreviousMonth = $previousMonth->getDaysOfMonth();
 
         // add difference to $weekStartsWith counting backwards from days of previous month (reorder so that lowest value first)
-        for ($i = $daysPreviousMonth - $diffToWeekStart; $i < $daysPreviousMonth; $i++) {
+        for ($i = $daysPreviousMonth - $diffToWeekStart; $i < $daysPreviousMonth; ++$i) {
             $days[] = new \DateTime($previousMonth->format('Y') . '-' . $previousMonth->format('m') . '-' . ($i + 1));
         }
 
         // add normal count of current days
         $daysMonth = $this->getDaysOfMonth();
-        for ($i = 1; $i <= $daysMonth; $i++) {
+        for ($i = 1; $i <= $daysMonth; ++$i) {
             $days[] = new \DateTime($this->format('Y') . '-' . $this->format('m') . '-' . ($i));
         }
 
@@ -274,7 +274,7 @@ class SmartDateTime extends \DateTime
         $remainingDays = 42 - $diffToWeekStart - $daysMonth;
         $nextMonth     = $this->createModify(0, 1);
 
-        for ($i = 1; $i <= $remainingDays; $i++) {
+        for ($i = 1; $i <= $remainingDays; ++$i) {
             $days[] = new \DateTime($nextMonth->format('Y') . '-' . $nextMonth->format('m') . '-' . ($i));
         }
 
diff --git a/Stdlib/Graph/Tree.php b/Stdlib/Graph/Tree.php
index 17d76e9fa..b7592f0d5 100644
--- a/Stdlib/Graph/Tree.php
+++ b/Stdlib/Graph/Tree.php
@@ -131,7 +131,7 @@ class Tree extends Graph
     {
         $depth = $this->getMaxDepth();
 
-        for ($i = 1; $i < $depth; $i++) {
+        for ($i = 1; $i < $depth; ++$i) {
             $nodes = $this->getLevel($i);
             callback($nodes);
         }
diff --git a/Uri/UriFactory.php b/Uri/UriFactory.php
index 6bb91431b..752573182 100644
--- a/Uri/UriFactory.php
+++ b/Uri/UriFactory.php
@@ -187,7 +187,7 @@ class UriFactory
             $comps  = [];
             $length = count($pars);
 
-            for ($i = 0; $i < $length; $i++) {
+            for ($i = 0; $i < $length; ++$i) {
                 $spl = explode('=', $pars[$i]);
 
                 if (isset($spl[1])) {
diff --git a/Utils/ArrayUtils.php b/Utils/ArrayUtils.php
index ab93a4a6e..30d9463a0 100644
--- a/Utils/ArrayUtils.php
+++ b/Utils/ArrayUtils.php
@@ -345,7 +345,7 @@ class ArrayUtils
         $sum   = 0;
         $array = array_values($array);
 
-        for ($i = $start; $i <= $count - 1; $i++) {
+        for ($i = $start; $i <= $count - 1; ++$i) {
             $sum += $array[$i];
         }
 
diff --git a/Utils/Barcode/C128Abstract.php b/Utils/Barcode/C128Abstract.php
index c77afc5e4..55105d2bd 100644
--- a/Utils/Barcode/C128Abstract.php
+++ b/Utils/Barcode/C128Abstract.php
@@ -350,7 +350,7 @@ abstract class C128Abstract
         $codeLength = 0;
         $length     = strlen($codeString);
         
-        for ($i = 1; $i <= $length; $i++) {
+        for ($i = 1; $i <= $length; ++$i) {
             $codeLength = $codeLength + (int) (substr($codeString, ($i - 1), 1));
         }
 
diff --git a/Utils/Compression/LZW.php b/Utils/Compression/LZW.php
index 80e58b98f..a48757e32 100644
--- a/Utils/Compression/LZW.php
+++ b/Utils/Compression/LZW.php
@@ -40,7 +40,7 @@ class LZW implements CompressionInterface
         }
 
         $length = strlen($source);
-        for ($i = 0; $i < $length; $i++) {
+        for ($i = 0; $i < $length; ++$i) {
             $c  = $source[$i];
             $wc = $w . $c;
 
@@ -70,7 +70,7 @@ class LZW implements CompressionInterface
         $entry      = '';
         $dictSize   = 256;
 
-        for ($i = 0; $i < 256; $i++) {
+        for ($i = 0; $i < 256; ++$i) {
             $dictionary[$i] = chr($i);
         }
 
@@ -78,7 +78,7 @@ class LZW implements CompressionInterface
         $result = $dictionary[$compressed[0]];
         $count  = count($compressed);
 
-        for ($i = 1; $i < $count; $i++) {
+        for ($i = 1; $i < $count; ++$i) {
             $k = $compressed[$i];
 
             if ($dictionary[$k]) {
diff --git a/Utils/Converter/Numeric.php b/Utils/Converter/Numeric.php
index 20b206f54..39314c9a7 100644
--- a/Utils/Converter/Numeric.php
+++ b/Utils/Converter/Numeric.php
@@ -75,7 +75,7 @@ class Numeric
         if ($toBaseInput === '0123456789') {
             $newOutput = 0;
 
-            for ($i = 1; $i <= $numberLen; $i++) {
+            for ($i = 1; $i <= $numberLen; ++$i) {
                 $newOutput = bcadd(
                     (string) $newOutput, 
                     bcmul(
@@ -168,7 +168,7 @@ class Numeric
     {
         $alpha = '';
 
-        for ($i = 1; $number >= 0 && $i < 10; $i++) {
+        for ($i = 1; $number >= 0 && $i < 10; ++$i) {
             $alpha   = chr(0x41 + ($number % pow(26, $i) / pow(26, $i - 1))) . $alpha;
             $number -= pow(26, $i);
         }
@@ -190,7 +190,7 @@ class Numeric
         $numeric = 0;
         $length  = strlen($alpha);
 
-        for ($i = 0; $i < $length; $i++) {
+        for ($i = 0; $i < $length; ++$i) {
             $numeric += pow(26, $i) * (ord($alpha[$length - $i - 1]) - 0x40);
         }
 
diff --git a/Utils/Encoding/Caesar.php b/Utils/Encoding/Caesar.php
index 52e995ac2..96ddd87b1 100644
--- a/Utils/Encoding/Caesar.php
+++ b/Utils/Encoding/Caesar.php
@@ -49,7 +49,7 @@ class Caesar
         $length    = strlen($source);
         $keyLength = strlen($key) - 1;
 
-        for ($i = 0, $j = 0; $i < $length; $i++, $j++) {
+        for ($i = 0, $j = 0; $i < $length; ++$i, $j++) {
             if ($j > $keyLength) {
                 $j = 0;
             }
@@ -75,7 +75,7 @@ class Caesar
         $length    = strlen($raw);
         $keyLength = strlen($key) - 1;
 
-        for ($i = 0, $j = 0; $i < $length; $i++, $j++) {
+        for ($i = 0, $j = 0; $i < $length; ++$i, $j++) {
             if ($j > $keyLength) {
                 $j = 0;
             }
diff --git a/Utils/Encoding/XorEncoding.php b/Utils/Encoding/XorEncoding.php
index a9b80e173..a5ceec793 100644
--- a/Utils/Encoding/XorEncoding.php
+++ b/Utils/Encoding/XorEncoding.php
@@ -42,7 +42,7 @@ final class XorEncoding
         $length    = strlen($source);
         $keyLength = strlen($key) - 1;
 
-        for ($i = 0, $j = 0; $i < $length; $i++, $j++) {
+        for ($i = 0, $j = 0; $i < $length; ++$i, $j++) {
             if ($j > $keyLength) {
                 $j = 0;
             }
diff --git a/Utils/Git/Repository.php b/Utils/Git/Repository.php
index 49164a72c..b12f72e43 100644
--- a/Utils/Git/Repository.php
+++ b/Utils/Git/Repository.php
@@ -819,7 +819,7 @@ class Repository
         $count   = count($lines);
         $commits = [];
 
-        for ($i = 0; $i < $count; $i++) {
+        for ($i = 0; $i < $count; ++$i) {
             $match = preg_match('/[0-9ABCDEFabcdef]{40}/', $lines[$i], $matches);
 
             if ($match !== false && $match !== 0) {
@@ -875,7 +875,7 @@ class Repository
         $commit->setRepository($this);
         $commit->setBranch($this->branch);
 
-        for ($i = 4; $i < $count; $i++) {
+        for ($i = 4; $i < $count; ++$i) {
             $commit->addFile($lines[$i]);
         }
 
diff --git a/Utils/RnG/Phone.php b/Utils/RnG/Phone.php
index 945154b05..a62287ec5 100644
--- a/Utils/RnG/Phone.php
+++ b/Utils/RnG/Phone.php
@@ -54,7 +54,7 @@ class Phone
 
         $numberParts = substr_count($layout['struct'], '$');
 
-        for ($i = ($isInt ? 2 : 1); $i < $numberParts; $i++) {
+        for ($i = ($isInt ? 2 : 1); $i < $numberParts; ++$i) {
             $numberString = str_replace(
                 '$' . $i, StringUtils::generateString($layout['size'][$i - 1][0], $layout['size'][$i - 1][1], '0123456789'), 
                 $numberString
diff --git a/Utils/RnG/StringUtils.php b/Utils/RnG/StringUtils.php
index 225334a74..6accd9c49 100644
--- a/Utils/RnG/StringUtils.php
+++ b/Utils/RnG/StringUtils.php
@@ -44,7 +44,7 @@ class StringUtils
         $charactersLength = strlen($charset);
         $randomString     = '';
 
-        for ($i = 0; $i < $length; $i++) {
+        for ($i = 0; $i < $length; ++$i) {
             $randomString .= $charset[mt_rand(0, $charactersLength - 1)];
         }
 
diff --git a/Utils/RnG/Text.php b/Utils/RnG/Text.php
index 072ff5939..f74461ee4 100644
--- a/Utils/RnG/Text.php
+++ b/Utils/RnG/Text.php
@@ -160,7 +160,7 @@ class Text
         $paid          = 0;
         $wordCount     = count($words);
 
-        for ($i = 0; $i < $length + 1; $i++) {
+        for ($i = 0; $i < $length + 1; ++$i) {
             $newSentence = false;
 
             $lastChar = substr($text, -1);
@@ -318,7 +318,7 @@ class Text
 
         $formatting = [];
 
-        for ($i = 0; $i < $length; $i++) {
+        for ($i = 0; $i < $length; ++$i) {
             $isCursive = (rand(0, 1000) <= 1000 * $probCursive ? true : false);
             $isBold    = (rand(0, 1000) <= 1000 * $probBold ? true : false);
             $isUline   = (rand(0, 1000) <= 1000 * $probUline ? true : false);
diff --git a/Utils/StringUtils.php b/Utils/StringUtils.php
index 7ebff34fa..9fc3be020 100644
--- a/Utils/StringUtils.php
+++ b/Utils/StringUtils.php
@@ -336,7 +336,7 @@ class StringUtils
         $count  = 0;
         $length = strlen($string);
 
-        for ($i = 0; $i < $length; $i++) {
+        for ($i = 0; $i < $length; ++$i) {
             if ($string[$i] !== $character) {
                 break;
             }
@@ -384,7 +384,7 @@ class StringUtils
         $l      = mb_strlen($input, 'UTF-8');
         $unique = [];
 
-        for ($i = 0; $i < $l; $i++) {
+        for ($i = 0; $i < $l; ++$i) {
             $char = mb_substr($input, $i, 1, 'UTF-8');
 
             if (!array_key_exists($char, $unique)) {
diff --git a/Validation/Finance/CreditCard.php b/Validation/Finance/CreditCard.php
index d61bdc11b..91ef0af57 100644
--- a/Validation/Finance/CreditCard.php
+++ b/Validation/Finance/CreditCard.php
@@ -49,7 +49,7 @@ abstract class CreditCard extends ValidatorAbstract
 
         // Loop through each digit and do the maths
         $total = 0;
-        for ($i = 0; $i < $numberLength; $i++) {
+        for ($i = 0; $i < $numberLength; ++$i) {
             $digit = $value[$i];
             // Multiply alternate digits by two
             if ($i % 2 == $parity) {
diff --git a/tests/Business/Marketing/NetPromoterScoreTest.php b/tests/Business/Marketing/NetPromoterScoreTest.php
index 9d631bcb5..d38d3ef21 100644
--- a/tests/Business/Marketing/NetPromoterScoreTest.php
+++ b/tests/Business/Marketing/NetPromoterScoreTest.php
@@ -28,15 +28,15 @@ class NetPromoterScoreTest extends \PHPUnit\Framework\TestCase
     {
         $nps = new NetPromoterScore();
 
-        for ($i = 0; $i < 10; $i++) {
+        for ($i = 0; $i < 10; ++$i) {
             $nps->add(mt_rand(0, 6));
         }
 
-        for ($i = 0; $i < 30; $i++) {
+        for ($i = 0; $i < 30; ++$i) {
             $nps->add(mt_rand(7, 8));
         }
 
-        for ($i = 0; $i < 60; $i++) {
+        for ($i = 0; $i < 60; ++$i) {
             $nps->add(mt_rand(9, 10));
         }
 
diff --git a/tests/Math/Geometry/ConvexHull/MonotoneChainTest.php b/tests/Math/Geometry/ConvexHull/MonotoneChainTest.php
index e0dad6058..67c69a468 100644
--- a/tests/Math/Geometry/ConvexHull/MonotoneChainTest.php
+++ b/tests/Math/Geometry/ConvexHull/MonotoneChainTest.php
@@ -22,8 +22,8 @@ class MonotoneChainTest extends \PHPUnit\Framework\TestCase
         self::assertEquals([['x' => 9, 'y' => 0]], MonotoneChain::createConvexHull([['x' => 9, 'y' => 0]]));
 
         $points = [];
-        for ($i = 0; $i < 10; $i++) {
-            for ($j = 0; $j < 10; $j++) {
+        for ($i = 0; $i < 10; ++$i) {
+            for ($j = 0; $j < 10; ++$j) {
                 $points[] = ['x' => $i, 'y' => $j];
             }
         }
diff --git a/tests/Utils/Encoding/CaesarTest.php b/tests/Utils/Encoding/CaesarTest.php
index 4c6c5a47b..5f852f8d1 100644
--- a/tests/Utils/Encoding/CaesarTest.php
+++ b/tests/Utils/Encoding/CaesarTest.php
@@ -20,7 +20,7 @@ class CaesarTest extends \PHPUnit\Framework\TestCase
 {
     public function testVolume()
     {
-        for ($i = 0; $i < 100; $i++) {
+        for ($i = 0; $i < 100; ++$i) {
             $raw = StringUtils::generateString(1, 100);
             $key = StringUtils::generateString(1, 100);
 
diff --git a/tests/Utils/Encoding/GrayTest.php b/tests/Utils/Encoding/GrayTest.php
index 0210eee5c..3338019a9 100644
--- a/tests/Utils/Encoding/GrayTest.php
+++ b/tests/Utils/Encoding/GrayTest.php
@@ -25,7 +25,7 @@ class GrayTest extends \PHPUnit\Framework\TestCase
 
     public function testVolume()
     {
-        for ($i = 0; $i < 100; $i++) {
+        for ($i = 0; $i < 100; ++$i) {
             $raw = mt_rand(0, 2040140512);
 
             self::assertEquals($raw, Gray::decode(Gray::encode($raw)));
diff --git a/tests/Utils/Encoding/XorEncodingTest.php b/tests/Utils/Encoding/XorEncodingTest.php
index 7ec46a892..6aff308b7 100644
--- a/tests/Utils/Encoding/XorEncodingTest.php
+++ b/tests/Utils/Encoding/XorEncodingTest.php
@@ -27,7 +27,7 @@ class XorEncodingTest extends \PHPUnit\Framework\TestCase
 
     public function testVolume()
     {
-        for ($i = 0; $i < 100; $i++) {
+        for ($i = 0; $i < 100; ++$i) {
             $raw = StringUtils::generateString(1, 100);
             $key = StringUtils::generateString(1, 100);
 
diff --git a/tests/Utils/RnG/DateTimeTest.php b/tests/Utils/RnG/DateTimeTest.php
index b29fe3249..03053367d 100644
--- a/tests/Utils/RnG/DateTimeTest.php
+++ b/tests/Utils/RnG/DateTimeTest.php
@@ -19,7 +19,7 @@ class DateTimeTest extends \PHPUnit\Framework\TestCase
 {
     public function testRnG()
     {
-        for ($i = 0; $i < 100; $i++) {
+        for ($i = 0; $i < 100; ++$i) {
             $dateMin = new \DateTime();
             $dateMax = new \DateTime();
 
diff --git a/tests/Utils/RnG/StringUtilsTest.php b/tests/Utils/RnG/StringUtilsTest.php
index e31dd02dc..73142c759 100644
--- a/tests/Utils/RnG/StringUtilsTest.php
+++ b/tests/Utils/RnG/StringUtilsTest.php
@@ -26,7 +26,7 @@ class StringUtilsTest extends \PHPUnit\Framework\TestCase
         $outOfBounds = false;
         $randomness  = 0;
 
-        for ($i = 0; $i < 10000; $i++) {
+        for ($i = 0; $i < 10000; ++$i) {
             $random = StringUtils::generateString(5, 12, '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()_?><|;"');
 
             if (strlen($random) > 12 || strlen($random) < 5) {