How to unpush array from arrays jQuery?

Question

This my code:

jQuery(document).on('click', '.list li', function(e){
    var container = $('#button');
    var selectedList = container.attr('data-selected-list');

    if(jQuery(this).hasClass('done')){
        jQuery(this).removeClass('done');

        var myElement = jQuery(this).attr('data-user-id');
        var myArray = selectedList;

        for (var i = myArray.length - 1; i >= 0; i--) {
          if (myArray[i] == myElement) myArray.splice(i, 1);
        }
        container.attr('data-selected-list', myArray);
    } else {
        jQuery(this).addClass('done');

        if (!selectedList) {
          selectedList = [];
        } else {
          selectedList = JSON.parse(selectedList);
        }

        selectedList.push(jQuery(this).attr('data-user-id'));
        selectedList = JSON.stringify(selectedList);

        container.attr('data-selected-list', selectedList);
    }
});

I successfully make when user click on .list li get the user id and add it as array into data-selected-list.

My question is how can make when unclick remove the user-id from data-selected-list (the array list)?

I search on stackoverflow but i failed to make this.

Use `indexOf()` to find the index of the element in the array, and `splice()` to remove the element from the array. — Barmar, Sep 14 '17 at 21:31
@Barmar I try but i failed can you help me on this by adding a final answer? — John Dors, Sep 14 '17 at 21:38
Sorry, can't post an answer to a closed question. If you edit the question to show what you tried, I can reopen it and post an answer with the correction. — Barmar, Sep 14 '17 at 21:48
You need to `JSON.stringify(myArray)` when storing it back into the attribute. — Barmar, Sep 14 '17 at 21:54

Barmar · Accepted Answer · 2017-09-14T22:05:03.770

0

You need to use JSON.parse() and JSON.stringify() when removing from the array, just like you do when you add to it.

if(jQuery(this).hasClass('done')){
    jQuery(this).removeClass('done');

    var myElement = jQuery(this).attr('data-user-id');
    var myArray = selectedList ? JSON.parse(selectedList) : [];

    for (var i = myArray.length - 1; i >= 0; i--) {
      if (myArray[i] == myElement) myArray.splice(i, 1);
    }
    container.attr('data-selected-list', JSON.stringify(myArray));
}

Another option would be to use .data() instead of .attr(). This stores the information internally in jQuery, and it can store any type.

edited Sep 14 '17 at 22:05

answered Sep 14 '17 at 21:59

Barmar

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Thanks but there's error: SyntaxError: missing : in conditional expression this error at (var myArray = selectedList ? JSON.parse(selectedList) ? [];) – John Dors Sep 14 '17 at 22:03
I fixed my typo – Barmar Sep 14 '17 at 22:05
really thank you I now learn from my mistakes thanks again :) – John Dors Sep 14 '17 at 22:07

How to unpush array from arrays jQuery?

1 Answers1