Setting an array key value in JavaScript

Question

This code obviously doesn't work in JavaScript, but how do I do this in JS?

It should be obvious from the code but I need to assign an array key value (so 'a', '5' and '8' in the example below) - unfortunately I do need to have a letter, so 0, 1, 2 etc. is no good.

I've seen something to do with objects and 'a':'op1' but it doesn't seem to work an I'm getting errors such as " Unexpected token : " - I bet this is easy when you know how?

var options = new Array('a' => 'op1', '5' => 'op2', '8' => 'op3');

for(x in options) {

    var value = options[x];

    alert("the key is " + value[0]);

    alert("the value is " + value[1]);

}

jQuery or native JS, whichever is best is fine (I'm using jQuery on that page anyway)

JCOC611 · Accepted Answer · 2013-03-05 23:26:40Z

3

To set the object:

var options = { 'a' : 'op1', '5' : 'op2', '8' : 'op3' }

In a for-in loop, the key is x and the value is options[x], not value[0] and value[1].

answered Mar 5, 2013 at 23:26

JCOC611

19.8k15 gold badges71 silver badges90 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

user2026796222222222 Over a year ago

Thanks to all. Excellent help from everybody, but this was first and it was the actual one I read which immediately solved the problem. Knew it was easy when you know how. Thanks again.

Michael W · Accepted Answer · 2013-03-05 23:44:41Z

2

It's JavaScript object literal notation:

var options = {
"a": "op1",
"5": "op2",
"8": "op3"
};

You should also be aware that the order of keys is not guaranteed, if you need the order to be specific you should keep the keys in an array and iterate by that. Also, if you iterate through an object you might want to make sure whether you are accessing properties of the current object or you are going through the prototype chain.

edited Mar 5, 2013 at 23:44

answered Mar 5, 2013 at 23:28

Michael W

6881 gold badge9 silver badges22 bronze badges

1 Comment

Michael W Over a year ago

@Dennis - true, my bad. Fixed it.

maerics · Accepted Answer · 2013-03-05 23:29:56Z

1

var options = {'a':'op1', '5':'op2', '8':'op3'};

for (var x in options) {
  alert("the key is " + x);
  alert("the value is " + options[x]);
}

answered Mar 5, 2013 at 23:29

maerics

157k47 gold badges277 silver badges299 bronze badges

Collectives™ on Stack Overflow

Setting an array key value in JavaScript

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related