Set an object property by using its value

Question

Say I call following function:

var query = makeQuery("email", "foo@bar.com");

The implementation I have is:

makeQuery = function (key, value) {
    return { key: value};
}

The object I end up with is: {"key": "foo@bar.com"}, which is obviously wrong. I would like to obtain {"email": "foo@bar.com"} instead. I tried setting it like so:

makeQuery = function (key, value) {
    return { JSON.stringify(key): value};
}

... but I get a "SyntaxError: Unexpected token ." I've also thought of using toString() and even eval(), without success. So my problem is to be able to set the property of the object returned in makeQuery() using its real value, that is, pick up the value of 'key', not setting the property with the 'key' literal.

Thanks for the help.

myDOMElement.setAttribute("attName","attValue"); might help also — Dragan Okanovic, Jul 07 '13 at 17:36

score 4 · Accepted Answer · answered Jul 07 '13 at 17:35

4

Create the object first and then use the square bracket syntax so you can set the property using the value of key:

makeQuery = function (key, value) {
    var query = {};
    query[key] = value;
    return query;
};

answered Jul 07 '13 at 17:35

James Allardice

164,175
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This one gets my vote because the function reads better. The other solutions work as well. Thanks for the help! – titusmagnus Jul 07 '13 at 17:42

score 0 · Answer 2 · answered Jul 07 '13 at 17:36

0

For variable keys in objects, use

var obj[key] = value

So then it becomes:

function makeQuery(key, value) {
    var obj = {};
    obj[key] = value;
    return obj;
}

answered Jul 07 '13 at 17:36

Schleis

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score 0 · Answer 3 · answered Jul 07 '13 at 17:36

0

define an object..

makeQuery = function (key, value) {
 var o = {};
 o[key] = value; 
 return o;
}

answered Jul 07 '13 at 17:36

cocco

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Set an object property by using its value

3 Answers3