Can I Revert to Original Array After Modification?

[drayarms]

The topic may sound vague, so please read on to get the details clarified.  Ok I have an array which I called deck as defined below.  I remove the last two elements from this array  using a function pop_array() that i constructed, and assign the resulting array (deck_minus_player1) to a new variable. Now I want to be able to manipulate both arrays, ie the original deck, and the new deck_minus_player1 created from it, independently.  But it seems as if, everytime I run the pop_array() function which creates the new array from the old, the old array automatically morphs into the new one and doesn't retain all its original contents. So how do I keep my old array (deck) with all its contents unscathed, even after I perform an operation on it?  Here's the code.

 

 

	<script type = "text/javascript" src="http://code.jquery.com/jquery-latest.js"> </script>


	<script type = "text/javascript">

		function pop_array(num_popped,array){

			for(i=0; i<num_popped; i++){

				array.pop(); 

			} 

			return array;

		}//Function end




		var deck = ["one","two","three","four","five"];

		var deck_minus_player1 = pop_array(2,deck);


		for(i=0; i<deck.length; i++){

			alert(deck[i]);

		}



	</script>

 

 

So when I run this code, the output is one, two, three  instead of one, two , three, four, five as I intended.  But if I eliminate the var deck_minus_player1 = pop_array(2,deck); line, i get desired results.

[Stooney]

pop modifies the original array.  So what's happening is you're changing the array, then copying it.  You want to copy it then change the copy. 

 

change this...

var deck_minus_player1 = pop_array(2,deck);

 

to this...

var deck_minus_player1 = deck;
pop_array(2, deck_minus_player1);

[drayarms]

@chrisdburns,  quite interesting. I hadn't thought of it that way.  I had earlier solved the problem like this

 

var new_deck = concat(deck); //Assigning the deck array to a new array called new_deck since deck is about to be modified

var deck_minus_player1 = pop_array(2,deck);

 

Your method seems cleaner though. I'm gonna try it.  Thanks