Best way to break from nested loops in Javascript?

Question

What's the best way to break from nested loops in Javascript?

//Write the links to the page.
for (var x = 0; x < Args.length; x++)
{
   for (var Heading in Navigation.Headings)
   {
      for (var Item in Navigation.Headings[Heading])
      {
         if (Args[x] == Navigation.Headings[Heading][Item].Name)
         {
            document.write("<a href=\"" 
               + Navigation.Headings[Heading][Item].URL + "\">" 
               + Navigation.Headings[Heading][Item].Name + "</a> : ");
            break; // <---HERE, I need to break out of two loops.
         }
      }
   }
}

Answer 1

Can you wrap that up in a function and then just return?

Answer 2

Just like Perl,

loop1:
    for (var i in set1) {
loop2:
        for (var j in set2) {
loop3:
            for (var k in set3) {
                break loop2;  // breaks out of loop3 and loop2
            }
        }
    }

as defined in EMCA-262 section 12.12.

Unlike C, these labels can only be used for continue and break, as Javascript does not have goto (without hacks like this).

Answer 3

var str = "";
for (var x = 0; x < 3; x++) {
    (function() {  // here's an anonymous function
        for (var y = 0; y < 3; y++) {
            for (var z = 0; z < 3; z++) {
                // you have access to 'x' because of closures
                str += "x=" + x + "  y=" + y + "  z=" + z + "<br />";
                if (x == z && z == 2) {
                    return;
                }
            }
        }
    })();  // here, you execute your anonymous function
}

How's that? :)

Answer 4

I'm a little late to the party but the following is a language-agnostic approach which doesn't use GOTO/labels or function wrapping:

for (var x = Set1.length; x > 0; x--)
{
   for (var y = Set2.length; y > 0; y--)
   {
      for (var z = Set3.length; z > 0; z--)
      {
          z = y = -1; // terminates second loop
          // z = y = x = -1; // terminate first loop
      }
   }
}

On the upside it flows naturally which should please the non-GOTO crowd. On the downside, the inner loop needs to complete the current iteration before terminating so it might not be applicable in some scenarios.

Answer 5

quite simple

var a=[1,2,3];
var b=[4,5,6];
var breakCheck1=false;

for (var i in a){
    for (var j in b){
        breakCheck1=true;
        break;
    }
    if (breakCheck1) {break;}
}