CODEWITHSUNDEEP
javascript
JS Lover
JS Lover

Reputation: 622

Is there a way to strip out a prototype method and make it work as a function?

Is there a way to make Array.prototype.map a function and call it as customMap(passitanyarray,function)

In general, is there a way to get Array.prototype.(whatever) and take whatever and make it your own function. for example like Array.prototype.map(function())

and extract map and use like this map([],function()) instead of Array.prototype.map(function())

I would explain more if that is not clear.

Thanks, In advance

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map#Polyfill

Upvotes: 0

Views: 36

Answers (2)

Mark
Mark

Reputation: 92440

If you're willing to manage the correct context of this with the function you could extract the call() function and provide it with the correct context. It's a little ugly (and I'm not sure it's wise), but it works and should work even with the polyfill:

let arr = [1, 2, 3]

/* get reference to properly bound call() */
let map = Function.call.bind(Array.prototype.map)

/* now you can use it like a regular function */
let double = map(arr, item => item * 2)
console.log(double)

Upvotes: 2

jo_va
jo_va

Reputation: 13963

You could wrap the arr.map() invocation like this:

function map(arr, fn) {
  return arr.map(fn);
}

console.log(map([1,2,3], x => x + 1));

Upvotes: 2

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