To check function exist or not we will use $.isFunction() of jQuery.
jQuery.isFunction(obj)
HTML
<!DOCTYPE html> <html> <head> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"> </script> <title>Check function exist before calling in jQuery </title> </head> </html>Javascript
$(document).ready(function(){ function myfunction() {} if (typeof myfunction !=='undefined' && $.isFunction(myfunction) ) { alert('myfunction exist'); } else { alert('myfunction does not exist') } if (typeof mycheck !=='undefined' && $.isFunction(mycheck)) { alert('mycheck exist'); } else { alert('mycheck does not exist') } });