I have simple code
sites_from_session = 12;
function function_name () {
var items_to_send = sites_from_session;
var template_name = jQuery('#new-site-template-name').val();
console.log(sites_from_session);
items_to_send.push(template_name);
console.log(sites_from_session);
}
function_name();
function_name();
function_name();
function_name();
function_name();
function_name();//...
The problem is that the push method pushes value to both arrays
Where i am wrong?
Arrays do not self clone in JavaScript. When you say something like
arr1 = arr2;
where both arr2 is a valid array, you haven't made an actual copy of arr2. All you've done is create a reference pointer to it for arr1. So when you make a change like
arr1[0] = "some value";
you are (in essence) saying the same thing as
arr2[0] = "some value";
To properly clone a separate copy you need to use this:
var items_to_send = sites_from_session.slice();
This will return a new array that holds all of the items from the original array.
It is a very common Javascript problem. The arrays are not copied like this:
var items_to_send = sites_from_session;
It merely copies the reference of the array to a new variable. In other words, items_to_send and sites_from_session are two names pointing to the same array in RAM. If you want to make a copy of the array (called deep copying) rather than just another pointer (shallow copying), you need to use slice():
//create a copy of the array
var items_to_send = sites_from_session.slice(0);
The rest of your code should work fine.
Possible duplication of this question: How do you clone an Array of Objects in Javascript?
You can learn more here: http://davidwalsh.name/javascript-clone-array
t have arrays in your code in first place.var items_to_send = sites_from_session;` where is second array?