How can I get variables before a dot?

Question

I want to get variables before a dot like this:

"hello".myFunction();

I want to get "hello". I tried using this code and I thought that this is obviously not gonna work.

function myFunction(){
  return value;
}

But it doesn't work. I always getting this error.

TypeError: "hello world".myFunction is not a function. (In '"hello world".myFunction()', '"hello world".myFunction' is undefined)

`hello` is a string which does not have `myFunction` method on it, why not simply pass `myFunction('hello')` and use it in `myFunction` — Code Maniac, Jun 07 '19 at 04:51
`"hello"` is not a variable, it's a string literal, resulting in a string value. Please provide a better explanation of what you are trying to do. If generally you want to get a reference to the object you are calling a method on, you can do that via `this`: `({foo: 42, bar() { console.log(this); }).bar()` — Felix Kling, Jun 07 '19 at 04:51

score 3 · Accepted Answer · answered Jun 07 '19 at 04:57

3

Using String.prototype and this keyword

String.prototype.myFunction = function() {
  document.body.innerText = this
}

"hello".myFunction();

answered Jun 07 '19 at 04:57

User863

19,346
2
17
41

Agoose Banwatti · Answer 2 · 2019-06-07T05:00:26.710

1

If you want to use it like toUpperCase(), try this.

String.prototype.myFunction = function() {
  return this.toUpperCase();
}

"abc".myFunction() // Evaluates to ABC

edited Jun 07 '19 at 05:00

answered Jun 07 '19 at 04:54

Agoose Banwatti

410
2
13

score 0 · Answer 3 · answered Jun 07 '19 at 05:34

As of now you are using a string and calling a user defined function on string. That can be accomplished by prototype overriding. So you can add one function on String object and use it. check this link....

Add method to string class

String.prototype.myFunction = function(a){

   return a;
}

"hello".myFunction("Done");

How can I get variables before a dot?

3 Answers3