diff --git a/algorithm/sorting/merge/basic/code.js b/algorithm/sorting/merge/basic/code.js
index d3d0a175..84ee70f5 100644
--- a/algorithm/sorting/merge/basic/code.js
+++ b/algorithm/sorting/merge/basic/code.js
@@ -3,74 +3,66 @@ tracer._sleep(1000);
 tracer._pace(500);
 
 function mergeSort(start, end) {
-    if (Math.abs(end - start) <= 1) {
-      return [];
-    }
-    
+    if (Math.abs(end - start) <= 1) return [];
     var middle = Math.ceil((start + end) / 2);
 
     mergeSort(start, middle);
     mergeSort(middle, end);
-    
-    tracer._print('divide left[' + start + ', ' + (middle-1) + '], right[' + (middle) + ', ' + (end-1) + ']');
 
+    tracer._print('divide left[' + start + ', ' + (middle - 1) + '], right[' + (middle) + ', ' + (end - 1) + ']');
     return mergeSort.merge(start, middle, end);
 }
 
-mergeSort.merge = function (start, middle, end) {
-    var left = Array();
-    var right = Array();
-
-    var leftSize = middle - start;
-    var rightSize = end - middle;
-    var maxSize = Math.max(leftSize, rightSize);
-    var size = end - start;
+mergeSort.merge = function(start, middle, end) {
+    const leftSize = middle - start;
+    const rightSize = end - middle;
+    const maxSize = Math.max(leftSize, rightSize);
+    const size = end - start;
+    var left = [];
+    var right = [];
     var i;
 
     for (i = 0; i < maxSize; i++) {
-      if (i < leftSize) {
-        left.push(D[start + i]);
-        tracer._select(start + i);
-        tracer._print('insert value into left array[' + i +'] = ' + D[start + i]);
-      }
-      if (i < rightSize) {
-        right.push(D[middle + i]);
-        tracer._select(middle + i);
-        tracer._print('insert value into right array[' + i +'] = ' + D[middle + i]);
-      }
+        if (i < leftSize) {
+            left.push(D[start + i]);
+            tracer._select(start + i);
+            tracer._print('insert value into left array[' + i + '] = ' + D[start + i]);
+        }
+        if (i < rightSize) {
+            right.push(D[middle + i]);
+            tracer._select(middle + i);
+            tracer._print('insert value into right array[' + i + '] = ' + D[middle + i]);
+        }
     }
     tracer._print('left array = [' + left.join(', ') + '],' + 'right array = [' + right.join(', ') + ']');
-    
+
     i = 0;
     while (i < size) {
-      if (left[0] && right[0]) {
-        if (left[0] > right[0]) {
-          D[start + i] = right.shift();
-          tracer._print('rewrite from right array[' + i + '] = ' + D[start+i]);
+        if (left[0] && right[0]) {
+            if (left[0] > right[0]) {
+                D[start + i] = right.shift();
+                tracer._print('rewrite from right array[' + i + '] = ' + D[start + i]);
+            } else {
+                D[start + i] = left.shift();
+                tracer._print('rewrite from left array[' + i + '] = ' + D[start + i]);
+            }
+        } else if (left[0]) {
+            D[start + i] = left.shift();
+            tracer._print('rewrite from left array[' + i + '] = ' + D[start + i]);
         } else {
-          D[start + i] = left.shift();
-          tracer._print('rewrite from left array[' + i + '] = ' + D[start+i]);
+            D[start + i] = right.shift();
+            tracer._print('rewrite from right array[' + i + '] = ' + D[start + i]);
         }
-      } else if (left[0]) {
-        D[start + i] = left.shift();
-        tracer._print('rewrite from left array[' + i + '] = ' + D[start+i]);
-      } else {
-        D[start + i] = right.shift();
-        tracer._print('rewrite from right array[' + i + '] = ' + D[start+i]);
-      }
-      
-      tracer._deselect(start + i);
-      tracer._notify(start + i);
-      
-      i++;
-    }
-    
-    tempArray = Array();
-    for (i=start; i<end; i++) {
-        tempArray.push(D[i]);
+
+        tracer._deselect(start + i);
+        tracer._notify(start + i);
+        i++;
     }
+
+    tempArray = [];
+    for (i = start; i < end; i++) tempArray.push(D[i]);
     tracer._print('merged array = [' + tempArray.join(', ') + ']');
-}
+};
 
-mergeSort(0, D.length)
+mergeSort(0, D.length);
 tracer._print('sorted array = [' + D.join(', ') + ']');
diff --git a/algorithm/sorting/quick/basic/code.js b/algorithm/sorting/quick/basic/code.js
index 825d2a40..84419726 100644
--- a/algorithm/sorting/quick/basic/code.js
+++ b/algorithm/sorting/quick/basic/code.js
@@ -1,6 +1,7 @@
 tracer._print('original array = [' + D.join(', ') + ']');
 tracer._sleep(1000);
 tracer._pace(500);
+
 function quicksort(low, high) {
     if (low < high) {
         var p = partition(low, high);
@@ -8,25 +9,29 @@ function quicksort(low, high) {
         quicksort(p + 1, high);
     }
 }
+
 function partition(low, high) {
     var pivot = D[high];
     tracer._selectSet([low, high]);
     var i = low;
+    var temp;
+    
     for (var j = low; j < high; j++) {
         if (D[j] <= pivot) {
-            var temp = D[i];
+            temp = D[i];
             D[i] = D[j];
             D[j] = temp;
             tracer._notify(i, j);
             i++;
         }
     }
-    var temp = D[i];
+    temp = D[i];
     D[i] = D[high];
     D[high] = temp;
     tracer._notify(i, high);
     tracer._deselectSet([low, high]);
     return i;
 }
+
 quicksort(0, D.length - 1);
-tracer._print('sorted array = [' + D.join(', ') + ']');
\ No newline at end of file
+tracer._print('sorted array = [' + D.join(', ') + ']');