Starting from JavaScript 1.2, a label can be used with break statement to control the flow more precisely. A label is simply an identifier followed by a colon (:) that is applied to a statement or a block of code.
Example
You can try to run the following code to learn how to work with labels with break statement
Live Demo
<html>
<body>
<script>
document.write("Entering the loop!<br /> ");
outerloop: // This is the label name
for (var i = 0; i < 5; i++) {
document.write("Outerloop: " + i + "<br />");
innerloop:
for (var j = 0; j < 5; j++) {
if (j > 3 ) break ; // Quit the innermost loop
if (i == 2) break innerloop; // Do the same thing
if (i == 4) break outerloop; // Quit the outer loop
document.write("Innerloop: " + j + " <br />");
}
}
document.write("Exiting the loop!<br /> ");
</script>
</body>
</html>