Js: assign arrow function name to variable

Question

I have an arrow function:

() => 'a'

Can I name this function by one of my variable, such that:

let func_name = 'a';

// expected output
// let a = () => 'a';

Do you mean ```let a = () => 'a';``` and then able to call it like ```a()```? — Tushar, Oct 02 '20 at 05:39
This sounds like [an XY problem](https://meta.stackexchange.com/questions/66377/what-is-the-xy-problem). What are you actually trying to do? — VLAZ, Oct 02 '20 at 05:41
Looks like a duplicate of https://stackoverflow.com/questions/5117127/use-dynamic-variable-names-in-javascript. — Dennis Hackethal, Oct 02 '20 at 05:55

Adam Azad · Accepted Answer · 2020-10-02T07:27:45.697

0

It is possible. Since everything, except for primitive types, is an object in JavaScript, you can do:

The not so right way, which is polluting the global or current namespace:

function func(){
  // func is an object, see Functions on MDN
  let func_name = 'a';

  this[func_name] = () => func_name;


  // To call it
  console.log(
    this[func_name]()
  );
}

func();

// func is an object, see Functions on MDN
let func_name = 'a';

// Object.freeze, so obj cannot be changed, similar to const
// Object.seal, the structure cannot be changed.
const obj = Object.freeze({
  [func_name]: () => func_name
})

obj[func_name] = "aaaaa"; // Throws an error in strict mode

// To call it
console.log(obj[func_name]());

Bear in mind that you can always reassign obj[func_name] to anything. Depending on the implementation, you can use Object.seal or Object.freeze

edited Oct 02 '20 at 07:27

answered Oct 02 '20 at 05:37

Adam Azad

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I'd advise against adding random values to `this`. In the current code, `this` is going to be `window`, so you're actually making all of these global. It makes it very likely that something will clash. Worse yet, if strict mode is enabled, this code will fail because `this` would be set to `undefined` and thus you'd get an error for trying to set a property on it. – VLAZ Oct 02 '20 at 05:50
@VLAZ, that's why I recommended another implementation; like `obj = { [func_name]: () => func_name }`. – Adam Azad Oct 02 '20 at 05:55
@AdamAzad but why use `this` at all if it's not recommended even by you? – VLAZ Oct 02 '20 at 06:13

Js: assign arrow function name to variable

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