javascript loop?

[birdboy272]

how do you make a loop that stops outputting after one item has been output from another loop?

[iam_clint]

example? cause i don't understand what your asking.

[gits]

i think you nested 2 loops for the purpose of comparing them or whatever, so you may have something like this:

var list1 = [1, 2, 3, 4, 5, 6];
var list2 = ['a', 'b', 'c', 3, 'd', 'e'];
 
for (var i in list1) {
    for (var j in list2) {
        if (list1[i] == list2[j]) {
            alert('found ' + list1[i] + ' in both lists');
    }
}
 

its a good idea to break the entire looping when the inner condition returns true ... so you may do the following:

var list1 = [1, 2, 3, 4, 5, 6];
var list2 = ['a', 'b', 'c', 3, 'd', 'e'];
 
outerloop: for (var i in list1) {
    for (var j in list2) {
        if (list1[i] == list2[j]) {
            alert('found ' + list1[i] + ' in both lists');
            break outerloop;
    }
}
 

but have in mind ... that this is not the best way to compare ... until you need two loops you may have n*m steps to do. what about n+m? ;) so have a look at the following possibilty:

var list1 = [1, 2, 3, 4, 5, 6];
var list2 = ['a', 'b', 'c', 3, 'd', 'e'];
var lookup = {};
 
for (var j in list2) {
    lookup[list2[j]] = list2[j];
}
 
for (var i in list1) {
    if (typeof lookup[list1[i]] != 'undefined') {
        alert('found ' + list1[i] + ' in both lists');
        break;
    } 
}
 

hope this helps ... ;)