diff --git a/src/algorithms/sorting/insertion-sort/InsertionSort.js b/src/algorithms/sorting/insertion-sort/InsertionSort.js
index 7a801613..83e79170 100644
--- a/src/algorithms/sorting/insertion-sort/InsertionSort.js
+++ b/src/algorithms/sorting/insertion-sort/InsertionSort.js
@@ -6,7 +6,7 @@ export default class InsertionSort extends Sort {
 
     // Go through all array elements...
     for (let i = 1; i < array.length; i += 1) {
-      let currentIndex = i;
+      let j = i;
 
       // Call visiting callback.
       this.callbacks.visitingCallback(array[i]);
@@ -14,23 +14,17 @@ export default class InsertionSort extends Sort {
       // Check if previous element is greater than current element.
       // If so, swap the two elements.
       while (
-        array[currentIndex - 1] !== undefined
-        && this.comparator.lessThan(array[currentIndex], array[currentIndex - 1])
+        array[j - 1] !== undefined
+        && this.comparator.lessThan(array[j], array[j - 1])
       ) {
         // Call visiting callback.
-        this.callbacks.visitingCallback(array[currentIndex - 1]);
+        this.callbacks.visitingCallback(array[j - 1]);
 
         // Swap the elements.
-        [
-          array[currentIndex - 1],
-          array[currentIndex],
-        ] = [
-          array[currentIndex],
-          array[currentIndex - 1],
-        ];
+        [array[j - 1], array[j]] = [array[j], array[j - 1]];
 
         // Shift current index left.
-        currentIndex -= 1;
+        j -= 1;
       }
     }
 
diff --git a/src/algorithms/sorting/quick-sort/QuickSortInPlace.js b/src/algorithms/sorting/quick-sort/QuickSortInPlace.js
index d02298b2..c780f9bf 100644
--- a/src/algorithms/sorting/quick-sort/QuickSortInPlace.js
+++ b/src/algorithms/sorting/quick-sort/QuickSortInPlace.js
@@ -39,9 +39,7 @@ export default class QuickSortInPlace extends Sort {
        * @param {number} rightIndex
        */
       const swap = (leftIndex, rightIndex) => {
-        const temp = array[leftIndex];
-        array[leftIndex] = array[rightIndex];
-        array[rightIndex] = temp;
+        [array[leftIndex], array[rightIndex]] = [array[rightIndex], array[leftIndex]];
       };
 
       const pivot = array[highIndex];
diff --git a/src/algorithms/sorting/shell-sort/ShellSort.js b/src/algorithms/sorting/shell-sort/ShellSort.js
index cdbba997..58859acb 100644
--- a/src/algorithms/sorting/shell-sort/ShellSort.js
+++ b/src/algorithms/sorting/shell-sort/ShellSort.js
@@ -12,22 +12,20 @@ export default class ShellSort extends Sort {
     while (gap > 0) {
       // Go and compare all distant element pairs.
       for (let i = 0; i < (array.length - gap); i += 1) {
-        let currentIndex = i;
+        let j = i;
         let gapShiftedIndex = i + gap;
 
-        while (currentIndex >= 0) {
+        while (j >= 0) {
           // Call visiting callback.
-          this.callbacks.visitingCallback(array[currentIndex]);
+          this.callbacks.visitingCallback(array[j]);
 
           // Compare and swap array elements if needed.
-          if (this.comparator.lessThan(array[gapShiftedIndex], array[currentIndex])) {
-            const tmp = array[currentIndex];
-            array[currentIndex] = array[gapShiftedIndex];
-            array[gapShiftedIndex] = tmp;
+          if (this.comparator.lessThan(array[gapShiftedIndex], array[j])) {
+            [array[j], array[gapShiftedIndex]] = [array[gapShiftedIndex], array[j]];
           }
 
-          gapShiftedIndex = currentIndex;
-          currentIndex -= gap;
+          gapShiftedIndex = j;
+          j -= gap;
         }
       }
 
diff --git a/src/data-structures/heap/Heap.js b/src/data-structures/heap/Heap.js
index b978739e..700d4fe9 100644
--- a/src/data-structures/heap/Heap.js
+++ b/src/data-structures/heap/Heap.js
@@ -95,9 +95,8 @@ export default class Heap {
    * @param {number} indexTwo
    */
   swap(indexOne, indexTwo) {
-    const tmp = this.heapContainer[indexTwo];
-    this.heapContainer[indexTwo] = this.heapContainer[indexOne];
-    this.heapContainer[indexOne] = tmp;
+    [this.heapContainer[indexOne], this.heapContainer[indexTwo]] = [
+      this.heapContainer[indexTwo], this.heapContainer[indexOne]];
   }
 
   /**