Merge pull request #10 from li-xinyang/patch-1

fix: Handle pop empty stack
kuychaco · Jun 25, 2017 · 58517aa · 58517aa
2 parents 22e8f8c + 6416d81
commit 58517aa
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/data-structures/stack.js b/data-structures/stack.js
@@ -67,6 +67,10 @@ Stack.prototype.push = function(value) {
 
 // O(1)
 Stack.prototype.pop = function() {
+  if (this._count === 0) {
+    return 'No element inside the stack. Add element before poping.'
+  }
+
   var value = this._storage[--this._count];
   delete this._storage[this._count];
   if (this._count < 0) {