Continue inside a forEach loop

Question

It is standard practice to continue inside a loop if a certain condition is met/unmet. In a Javascript forEach loop, this produces a syntax error:

const values = [1, 2, 3, 4, 5];
values.forEach((value) => {
    if (value === 3) { continue; }
    console.log(value);
})

SyntaxError[ ... ]: Illegal continue statement: no surrounding iteration statement

This happens whether I use function or an arrow function. How can you continue inside a forEach loop?

Obviously, you could do an inverse case (if (value !== 3) { ... }), but that is not what I'm looking for.

`forEach()` isn't a loop, it's a function. If you want a loop, use `for (const value of values) { … }` — robertklep, Jun 27 '22 at 16:54
@Ouroborus `return` rather than `continue` does work correctly (+1) - it's behavior is not immediately obvious, however. It's easy to think that you are returning the parent function instead of the arrow function within the `forEach`. — Chris Collett, Jun 27 '22 at 18:13

score 2 · Accepted Answer · edited Aug 09 '22 at 15:10

2

As @robertklep stated forEach() is not a loop, it is a function. You cannot use the continue keyword inside a forEach loop because its functionality is meant to loop each item in the array.

To achieve the similar behavior you can use,

  for(let item of values){
     if (item === 3) { 
      continue;
     }
     console.log(item);
  }

edited Aug 09 '22 at 15:10

marc_s

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answered Jun 27 '22 at 17:03

Shashan Sooriyahetti

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So is there any benefit to using `forEach` versus a `for ... of ... ` loop? – Chris Collett Jun 27 '22 at 18:10
1

@ChrisCollett depends on your requirement. for more information read the answer https://stackoverflow.com/questions/43031988/javascript-efficiency-for-vs-foreach – Shashan Sooriyahetti Jun 28 '22 at 09:59

pastaleg · Answer 2 · 2022-06-27T16:59:04.687

1

For practical purposes, return in a forEach() callback is equivalent to continue in a conventional for loop but it isn't the most idiomatic use of functional programming patterns

To solve that, you can filter before you loop:

const values = [1, 2, 3, 4, 5];
values.filter(v => v !== 3).forEach((value) => {
    console.log(value);
})

edited Jun 27 '22 at 16:59

answered Jun 27 '22 at 16:58

pastaleg

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Continue inside a forEach loop

2 Answers2