Please explain this usage of a colon in javascript

Question

I\'m making a library, and I often inspect the result of Closure Compiler\'s output to see how it\'s doing things (I do have unit tests, but I still like to see the compiled

Answer 1

It is a label

Provides a statement with an identifier that you can refer to using a break or continue statement.

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.

Another common place you see it is when people stick the wonderful and useless javascript: on event handlers.