Breaking out of a 2-level FOR loop

**Lasse Reichstein Nielsen** · Jul 20 '05, 11:56 AM

Re: Breaking out of a 2-level FOR loop

"Dennis M. Marks" <denmarks@dcsi. net> writes:
[color=blue]
> My search will be FOR (i=0 etc , FOR (j= 0 etc.
> The limit will be the number of items in the array level. How do I
> break out of the FOR loops when I find a match?[/color]

You use the "break" statment. It breaks out of the closest enclosing
loop or switch (for, while, do or switch statements).

---
for (...) {
if (whatever) {break;}
}
---
[color=blue]
> Most languages have an EXIT statement. It there one in javascript?[/color]

Yep, break.
[color=blue]
> I must break out of 2 FOR loops when I find a match. It would be a
> waste of time to complete the loops.[/color]

For that you need a label on the outer loop, and a label argument
to the break command.

---
OuterLoopLabel:
for(...) {
for(...) {
if (whatever) {break OuterLoopLabel; }
}
}
---

That should be enough escaping for this problem.

If you ever need a quick escape from nested function calls, you can
use exceptions:
---
function recursion(n) {
if (n<10) {recursion(n+1) ;}
else {throw n;}
}

try {
recursion(0);
} catch (n) {
alert(n);
}
---

/L
--
Lasse Reichstein Nielsen - lrn@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>
'Faith without judgement merely degrades the spirit divine.'

**Douglas Crockford** · Jul 20 '05, 11:56 AM

Re: Breaking out of a 2-level FOR loop

> I have a 3 level array. First level is a list of trains. Second level[color=blue]
> are items about the train. Third level is where there are multiples of
> the second level item.
>
> The search will be of myArray[i][2][j]
>
> i is train entry, 2 is the item i'm searching and j are the individial
> items.
>
> My search will be FOR (i=0 etc , FOR (j= 0 etc.
> The limit will be the number of items in the array level. How do I
> break out of the FOR loops when I find a match? Most languages have an
> EXIT statement. It there one in javascript? I must break out of 2 FOR
> loops when I find a match. It would be a waste of time to complete the
> loops.[/color]

You could just read the manual, you know.
For statements can have labels.

outer: for (...) {
....
break outer;
....
}

JavaScript: A Survey of the Language

http://www.crockford.com/javascript/survey.html

**Dr John Stockton** · Jul 20 '05, 11:57 AM

Re: Breaking out of a 2-level FOR loop

JRS: In article <17112003183230 4785%denmarks@d csi.net>, seen in
news:comp.lang. javascript, Dennis M. Marks <denmarks@dcsi. net> posted at
Mon, 17 Nov 2003 18:32:30 :-
[color=blue]
> I must break out of 2 FOR
>loops when I find a match.[/color]

To avoid use of a label, you can put the FOR loops in a function and use
return.

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
<URL:http://jibbering.com/faq/> Jim Ley's FAQ for news:comp.lang. javascript
<URL:http://www.merlyn.demo n.co.uk/js-index.htm> JS maths, dates, sources.
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Breaking out of a 2-level FOR loop

Breaking out of a 2-level FOR loop

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