Explicit type casting in js

Question

Is there a generic way to explicitly cast a variable to a specific type? For example:

var b = true;
var str = "";
var n = 5;
cast(someVariable, typeof b);   //someVariable become a boolean
cast(someVariable, typeof str); //someVariable become a string
cast(someVariable, typeof n);   //someVariable become an integer

where a cast is supposed to be that magic casting method.

That's obvious that I can just enumerate in a switch all possible types. But is there a [beautiful] native way to do that?

Can't you use something like Boolean( someVariable ), Number( someVariable ); ? — Mohit Bhardwaj
– Mohit Bhardwaj, Commented Jul 20, 2016 at 10:31
@MohitBhardwaj I can, but the thing is I don't always know the type of second argument. — Kris.K
– Kris.K, Commented Jul 20, 2016 at 10:37

Arun Ghosh · Accepted Answer · 2016-07-20 10:32:17Z

4

You can do it using mapping:

var castMap  = {
    "boolean" : Boolean
};
var b = true;
var someVariable = "true";
castMap[typeof(b)](someVariable)

answered Jul 20, 2016 at 10:32

Arun Ghosh

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2 Comments

Kris.K Over a year ago

yeah, that looks more simple than switch operator. Thank you

SkyLeach Over a year ago

This isn't a good answer. Number(val) doesn't cast types like in c.

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