Arrow function alternative

Question

What is the arrow function alternative to this function ?

function(entry) {
  //
}(entry);

I tried some things like below, but it's not the correct way :

entry => {
   //
}(entry)

[MDN Web Docs: Arrow Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions) - Compare the two examples they provide, i.e., `function (a){ return a + 100; }` to `(a) => { return a + 100; }`. — HoldOffHunger, Oct 20 '20 at 17:16
This *is* the correct alternative. How did you test it? Why do you think it is not correct? — VLAZ, Oct 20 '20 at 17:19
Again, your two pieces of code are *the same*. Both will work as function expressions. They cannot work when placed in a non-expression context but again, both will behave that way. — VLAZ, Oct 20 '20 at 17:22
A linter error is not the same as "it doesn't work" but "it is not allowed by my style enforcing tool". The code works [Playground Link](https://www.typescriptlang.org/play?#code/MYewdgzgLgBApmKAnAnjAvDArAbgFB4AUAZgK5jBQCW4hCyKAlDAN54wyiQgA2cAdDxABzOolSN8AX0ZiGkgnNQYAfK3adwEXgKGj6E6bINM8QA) - if you have any rules that prevent compilation, you should have mentioned them. You can likely change your style enforcing rule. — VLAZ, Oct 20 '20 at 17:27
Also, for completeness, neither the [normal function](https://www.typescriptlang.org/play?#code/MYewdgzgLgBApmKAnAnjAvDArAbgFB4BmArmMFAJbgAUCyKAlDAN54wyiQgA2cAdNxABzWolQN8AX1H0JQA) nor the [arrow function](https://www.typescriptlang.org/play?#code/MYewdgzgLgBApmKAnAnjAvDArAbgFB4LJroB8MA3njDKJCADZwB0DIA5gBRGoCU+AX26I+eIA) work when not placed in expression-only context. — VLAZ, Oct 20 '20 at 17:29
@ElectricShadow same thing with the normal function. It will not be a valid function declaration otherwise, so it will fail as well. — VLAZ, Oct 20 '20 at 17:33
@ElectricShadow it's OK I need to wrap the functions with parentheses. Thanks ! — Jerome, Oct 21 '20 at 06:26

score 3 · Accepted Answer · answered Oct 20 '20 at 17:18

3

Maybe you are mentioning IIFE (Immediately Invoked Function Expression)

;(function (entry) {
  console.log(entry)
})("abc")

;((entry) => {
  console.log(entry)
})("def")

answered Oct 20 '20 at 17:18

hgb123

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1

Notice the two things to learn from this answer are: 1) use parens to disambiguate what's being invoked, 2) don't invoke with the argument name, which is undefined outside the function – danh Oct 20 '20 at 17:31

score 0 · Answer 2 · answered Oct 20 '20 at 17:32

Take a look at the two examples provided at MDN Web Docs: Arrow Functions.

Function styling...

function (a){
   return a + 100;
}

Arrow functions...

(a) => {
   return a + 100;
}

Your code should then just work with...

entry => {
   //
}

As mentioned by others, your syntax is probably based on an IIFE (Immediately Invoked Function Expression) statement.

Arrow function alternative

2 Answers2