Break _.each loop

Question

How to break _.each() loop? Tried with _.every(), it is looping through the data only once.

Sample code:

    _.each([1,2,3,4,5],function(num){ 
       if(num < 3)
          console.log(num)
       else{
          console.log(num);
          return false;
       }
   });

Output: 1 2 3 4 5

    _.every([1,2,3,4,5],function(num){ 
       if(num < 3)
          console.log(num)
       else{
          console.log(num);
          return false;
       }
   });

Output: 1 false

Really, you shouldn't use a foreach if you may need to return early. Just use a regular `for` in that case. — Carcigenicate, Jul 25 '17 at 15:20
What are you actually trying to do? Return whether or not all numbers are less than three, or...? — Dave Newton, Jul 25 '17 at 15:23
Its just an sample code I have added. My project has different array data of html elements in which after specific condition it should return from the loop. — smita chougale, Jul 25 '17 at 15:25
@smitachougale How about being more specific? The question smells like a [XY problem](https://meta.stackexchange.com/questions/66377/what-is-the-xy-problem)! — Ram, Jul 25 '17 at 15:29
You'll want to explicitly `return true` from the `if` case in your `every` loop — Bergi, Jul 25 '17 at 15:45

score 2 · Answer 1 · answered Jul 25 '17 at 15:21

2

You cannot escape from the functional forEach loop.

Consider using a regular for loop instead.

const arr = [1,2,3,4,5];

for (let i = 0; i < arr.length; ++i) {
    const num = arr[i];
    if(num < 3) {
       console.log(num)
    } else {
       console.log('break out');
       break;
    }
}

answered Jul 25 '17 at 15:21

Naftali

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In fact you can.. `var break = false; _.each([...],(num)=>{ if(break) return [...] break = true; });` – Bellian Jul 25 '17 at 15:24
@Bellian it will still be in the loop though an then have an extra if check for break..... – Naftali Jul 25 '17 at 15:24
Indeed i cant advise to do so but it is possible. Just for completion (didn't downvote btw..) – Bellian Jul 25 '17 at 15:26
1

But again, that is not a loop break. Still looping ;-) – Naftali Jul 25 '17 at 15:27
True. But does not perform :/ – Bellian Jul 25 '17 at 15:29
@Bellian If you want the ugly "solution" for breaking from a `each` callback "loop", use exceptions. See [this question](https://stackoverflow.com/q/2641347/1048572) for details. But really, one should just not use `forEach` in that case. – Bergi Jul 25 '17 at 15:48

Break _.each loop

1 Answers1