Create a Stack Class - failing peek and pop

JavaScript
1

Tell us what’s happening:
Why am I failing my peek and pop test? for the pop case I literally used Array.pop() and it still failed;

Your code so far


function Stack() { 
    var collection = [];
    this.print = function() {
        console.log(collection);
    };
    // Only change code below this line
    this.peek = function(){
        var temp = collection.pop();
        collection.push(temp);
        return temp;
    }
    this.push = function(){

    }
    this.pop = function(){
        console.log(collection);
        var temp = collection.pop();
        console.log(collection);
        return temp;
    }
    this.isEmpty = function(){
        if(collection.length == 0){
            return true;
        }
        return false;
    }
    this.clear = function(){
        collection = [];
    }
    // Only change code above this line
}

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/coding-interview-prep/data-structures/create-a-stack-class

2 
this.peek = function(){
        var temp = collection.pop();

If you’re peeking, you can’t mutate the collection. Though I see you are pushing it back. Though I thought the purpose of this challenge was to not use push, pop, and others like that. Instead, you would manually manage that array through the use of indexes.

3

Aside from my previous comment, you should also flesh out your push method. It should help you pass the tests.