Core JavaScript 1.5 Guide:Loop Statements:label Statement

From MDC

[edit] label Statement

A label provides a statement with an identifier that lets you refer to it elsewhere in your program. For example, you can use a label to identify a loop, and then use the break or continue statements to indicate whether a program should interrupt the loop or continue its execution.

The syntax of the label statement looks like the following:

label :
   statement

The value of label may be any JavaScript identifier that is not a reserved word. The statement that you identify with a label may be any statement.

Example
In this example, the label markLoop identifies a while loop.

markLoop:
while (theMark == true)
   doSomething();
}