how to stop Javascript forEach?
This question already has an answer here:
You can't break from a forEach . I can think of three ways to fake it, though.
1. The Ugly Way : pass a second argument to forEach to use as context, and store a boolean in there, then use an if . This looks awful.
2. The Controversial Way : surround the whole thing in a try-catch block and throw an exception when you want to break. This looks pretty bad and may affect performance, but can be encapsulated.
3. The Fun Way : use every() .
['a', 'b', 'c'].every(function(element, index) {
// Do your thing, then:
if (you_want_to_break) return false
else return true
})
You can use some() instead, if you'd rather return true to break.
Breaking out of Array#forEach is not possible. (You can inspect the source code that implements it in Firefox on the linked page, to confirm this.)
Instead you should use a normal for loop:
function recurs(comment) {
for (var i = 0; i < comment.comments.length; ++i) {
var subComment = comment.comments[i];
recurs(subComment);
if (...) {
break;
}
}
}
(or, if you want to be a little more clever about it and comment.comments[i] is always an object:)
function recurs(comment) {
for (var i = 0, subComment; subComment = comment.comments[i]; ++i) {
recurs(subComment);
if (...) {
break;
}
}
}
As others have pointed out, you can't cancel a forEach loop, but here's my solution:
ary.forEach(function loop(){
if(loop.stop){ return; }
if(condition){ loop.stop = true; }
});
Of course this doesn't actually break the loop, it just prevents code execution on all the elements following the "break"
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