Arrow function confusion

Question

I was doing a question on codesignal and when I couldn't get the answer myself for all tests, revealed the answers and saw this one; while I understand what it's trying to do (make sure positions are not divisible by n, and if it is increment n by one) I'm having trouble understanding the arrow function syntax and, rewriting it myself from their code.

function obst(inputArray) {
for (var n=1;;n+=1) if(inputArray.every(x=>x%n)) return n;}

it basically says "for each x, return x%n", modifying the response. read more about it at the spec - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions — Ben Yitzhaki, Dec 17 '18 at 14:56
Can you clarify your question? Do you want help on how to write this as an arrow function? — Dmitriy, Dec 17 '18 at 14:56
The title of your question is very similar to one of the **bad** examples on the [ask] page. — Ivar, Dec 17 '18 at 14:59

score 1 · Answer 1 · answered Dec 17 '18 at 14:59

In Javascript, every function written like this:

function(args) {
   // DO SOME STUFF
}

can be written like this:

(args) => {// DO SOME STUFF}

In your case, the method .every() expects a function, and

function(x) {
    return x%n;
}

is written as

x => x%n

Egg · Answer 2 · 2018-12-17T15:34:23.153

0

inputArray.every(x=>x%n)

is the same as

inputArray.every(function (x){
  return x%n
}))

( except for the way the 'this' keyword works )

edited Dec 17 '18 at 15:34

answered Dec 17 '18 at 14:57

Egg

39
1
4

score 0 · Answer 3 · edited Dec 17 '18 at 17:07

For any doubt about Javascript language, i recommend the You Dont Know Js series written by Kyle Simpson.

It's a very enlightening book.

Tip: When you write a code, ask question to youself like:

what i'm doing?
assigment means equality?
what are the methods that can i use in string variables?

And something like that.

Stimulate yourself to know what in the actual fudge, you are doing.

Cheers!.

Arrow function confusion

3 Answers3