javascript function call - nested functions

Question

I am trying to implement the following in js:

 function Stack() {
 var top = null;
 var count = 0;
 //returns the total elements in an array
 this.getCount = function() {
 return count;
 }
 this.Push = function(data){
 var node = {
 data: data,
 next: null
 }
 node.next = top;
 top = node;
 count++;
 console.log("top: " + top,"count: " + count); 
 }
 }
 Stack.Push(5);

The call to Stack.Push is throwing an error, I think it is function scoping, right? How can I make the call to the push method?

• akinuri: var sth = new Stack(); sth.Push(5);

Answer 1

You need to create an object instance of the function

var stack = new Stack();
stack.push(5);

Answer 2

You must create an instance of Stack:

function Stack() {
 var top = null;
 var count = 0;
 //returns the total elements in an array
 this.getCount = function() {
 return count;
 }
 this.Push = function(data){
 var node = {
 data: data,
 next: null
 }
 node.next = top;
 top = node;
 count++;
 console.log("top: " + top,"count: " + count); 
 }
}
var instance = new Stack();
console.log(instance.Push(5));