javascript-tutorial / javascript-tutorial/en.javascript.info
The arrow function.... The lookup of this is made exactly the same way as a regular variable search: in the outer lexical environment.
- Dominant language
- HTML
- Stars
- 25.5k
- Forks
- 4k
- PR merge metrics
- No merged PRs in 30d
Description
I have tried to test this, i believe arrow function doesn't look up for 'this', in the outer lexical environment, it remembers the 'this' of the place where it is defined.
In the below code: arrow function is passed to another function and that function calls the arrow function at line //**. At line //** 'this' is 'window', so if arrow function looks up for this in outer lexical environment, then 'this' should be window object, not cl_Test.
Hence, i believe the statement put by you in arrow functions revisited should be changed. Please correct me if i am wrong.
function cl_Test() {
// let name = 'Pradeep';
this.name = 'Pradeep';
this.age = '31';
this.arrowF = () => {
console.log(`${this.name + ' ' + this.age}`);
};
this.normalF = function () {
console.log(name)
};
this.arrowF2 = () => {
console.log(name);
}
};
function fTest(f1) {
f1(); // **
};
let o1 = new cl_Test();
o1.name = 'Sunil';
o1.age = '34';
fTest(o1.arrowF); //*
fTest(o1.normalF);
fTest(o1.arrowF2);
Contributor guide
No contributing guide indexed for this repository
Research direction
Start by reading the “arrow functions revisited” section referenced in the issue and compare its statement about how arrow functions obtain this with the supplied example. Verify the behavior of arrowF and normalF when passed to fTest, then update the explanation so it accurately describes lexical this.】【。
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- documentation
- Issue type
- Documentation
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100