Console.log javascript [Function]

Question

I am trying to register a function in javascript:

console.log(callback) >>[Function] 

I want to see what this function is. I can do it? Thank.

Answer 1

If this is a user-defined function, you can use:

 console.log(callback.toString()); 

Otherwise, you just get something like [native code] , since the built-in functions are not written in JavaScript.

Example:

 function x(){} // Prints "function x(){}" (function(callback){ console.log(callback.toString()); })(x);