[JavaScript]Check is Function

When I was looking at the code at work, I found code like the one below while setting up a callback function.

if($.isFunction(callback)){
    callback();
}

The above writing method is actually jQuery.
You can also write in JavaScript.To check whether the value passed in i a function, use stypeof.

function(callBack)    
{
    ...
    if(typeof callBack == 'function') {
        callBack();
    }
}

jQuery's $.isFunction … return boolean
typeof … returns a string of type

I think that it is good to check the type by the basic typeof.

#JavaScript