Array acting weird?

Question

I've got the following code:

$(document).ready(function(){
    var array = [{"x": 0}];
    array[0] = {"x": 10};
    console.log(array);
    array[0] = {"x": 20};
    console.log(array);
});

With this I expect the output in the console to be:

[
    {
        0: {"x": 10}
    }
]

[
    {
        0: {"x": 20}
    }
]

But instead it is:

[
    {
        0: {"x": 20}
    }
]

[
    {
        0: {"x": 20}
    }
]

Does anyone have any idea why? Am I missing something?

JSFiddle: https://jsfiddle.net/6nfdmt91/

Actually, the output is **not** what you wrote in your question. — Gerardo Furtado, Oct 15 '17 at 23:59
The console is not a snapshot when logging arrays/objects .... it shows live objects that still have inheritance — charlietfl, Oct 16 '17 at 00:00
*"With this I expect the output in the console to be"* <- what makes you think you'd have numeric object keys? All you should expect to see is something like `[{x: 10}]` or `[{x: 20}]` — Phil, Oct 16 '17 at 00:00
@charlietfl Shouldn't the console log give the value of the current array? — L Ja, Oct 16 '17 at 00:03
@LJa yes but if you modify same array after logging to console it will show live version...including changes — charlietfl, Oct 16 '17 at 00:06
Duplicate of this question: https://stackoverflow.com/questions/11284663/console-log-shows-the-changed-value-of-a-variable-before-the-value-actually-ch — Nick, Oct 16 '17 at 00:08
@snapjs I believe the question I chose as a duplicate is better, because it addresses the console.log issue explicitly. — Gerardo Furtado, Oct 16 '17 at 00:10
@LJa what do you want to achieve? Keep the old state of an array? You can save it: https://jsfiddle.net/6nfdmt91/3/ — Gerardo Furtado, Oct 16 '17 at 00:11

score -5 · Answer 1 · answered Oct 16 '17 at 00:04

-5

try:

$(document).ready(function(){
 var array = [{"x": 0}];
 array[0] = {"x": 10};
 console.log(array);
 array[0].push({"x": 20});
 console.log(array);
});

Using Array.push() will "push" a new element.

answered Oct 16 '17 at 00:04

Daniel

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Array acting weird?

1 Answers1