[1,2,3].forEach(function(el) {
if(el === 1) break;
});
How can I do this using the new forEach
method in JavaScript? I've tried return;
, return false;
and break
. break
crashes and return
does nothing but continue iteration.
There's no built-in ability to break
in forEach
. To interrupt execution you would have to throw an exception of some sort. eg.
var BreakException = {};
try {
[1, 2, 3].forEach(function(el) {
console.log(el);
if (el === 2) throw BreakException;
});
} catch (e) {
if (e !== BreakException) throw e;
}
JavaScript exceptions aren't terribly pretty. A traditional for
loop might be more appropriate if you really need to break
inside it.
Array#some
Instead, use Array#some
:
[1, 2, 3].some(function(el) {
console.log(el);
return el === 2;
});
This works because some
returns true
as soon as any of the callbacks, executed in array order, return true
, short-circuiting the execution of the rest.
some
, its inverse every
(which will stop on a return false
), and forEach
are all ECMAScript Fifth Edition methods which will need to be added to the Array.prototype
on browsers where they're missing.