-
-
Save lyuehh/5034919 to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
function once(fn) { | |
var called = false; | |
return function() { | |
if(called) throw new Error('Callback was already called.'); | |
called = true; | |
fn.apply(null, arguments); | |
}; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment