Use key's value as key in key-value pair in a Javascript function param

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Use key’s value as key in key-value pair in Javascript

As a followup to Use key's value as key in key-value pair in Javascript function parameter. How can you use the value of a key-value pair as the key in a different key-value pair in a Javascript function param?

I'd like to do the following:

var params = {param1: "paramname1"};
somefunction({params.param1:"param1value"});

So that things essentially equals:

somefunction({"paramname1":"param1value"});

Uhm... exactly the same way. It's the same question as far as I can see. It has nothing to do with functions, just how to create the object literal properly. You cannot use variables as keys in object literals, hence you cannot use it this way. You have to create the object first and then pass it to the function. — Felix Kling, Dec 31 '12 at 15:40

score 4 · Accepted Answer · answered Dec 31 '12 at 15:40

4

To use an expression as a property name you need to use the [] syntax instead of an object literal:

var params = {
    param1: "paramname1"
};
var data = {};
data[params.param1] = "param1value";
somefunction();

answered Dec 31 '12 at 15:40

ThiefMaster

There's no way to put this in one line? – Eugene Dec 31 '12 at 15:42
Well, you can remove the linebreaks. But that will just make it ugly. So no, you cannot do this using just a single *statement*. – ThiefMaster Dec 31 '12 at 15:43
@user389823: Not in a readable way. – Felix Kling Dec 31 '12 at 15:43
Do you know why you can't use the object constructor? – bcurcio Dec 31 '12 at 15:43
3

@user389823: And of course you can always create your own functions which hide this behaviour but essentially, that's what you have to do. – Felix Kling Dec 31 '12 at 15:46
I'll make a wrapper function then. Thanks everyone. – Eugene Dec 31 '12 at 15:48

1 Answers1