CODEWITHSUNDEEP
javascriptthiscallprimitive
juffel
juffel

Reputation: 1115

Javascript Function.prototype.call() pass primitive value

I want to pass an index-variable as this to a function I call with function.call().

var fun = function() {
    console.log( this );
}

fun.call( 1 );
// -> Number {[[PrimitiveValue]]: 1}

So obviously the primitive integer 1 is not passed as primitive to the called function.
According to MDN for Function.prototype.call() "[...] primitive values will be converted to objects."

Is there a way to pass it to fun() as primitive integer?

Upvotes: 0

Views: 245

Answers (2)

kingshuk basak
kingshuk basak

Reputation: 421

Well what you want is never possible as per the definition of this inside a function. Yes there can be way arounds as given in the other answers for your implementation.

Upvotes: 1

Nikhilesh Shivarathri
Nikhilesh Shivarathri

Reputation: 1670

In the above example 1 is passed as an integer param but internally it is a object of number type to the fun function. So in order to access the value of integer from this. Use this.valueOf(). I think this helps you!

var x = 12;

function fun() {
  console.log(this.valueOf());
}

fun.call(x)

Upvotes: 1

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