Delegate in Javascript

I'm having a function where I need to call another function which will be dynamic and I just know the fu开发者_StackOverflow中文版nction name.

For example, my function is

myfunction(obj){
otherfunction(?);
}

otherfunction maybe

otherfunction(obj){
}

or

otherfunction(){
}

I don't know whether to pass the parameter or not.

How can I call the method?

---

you can call javascript functions with any count of arguments:

function myFunction ( firstValue, secondValue )
{
  if ( firstValue ) alert ( firstValue );
  if ( secondValue ) alert ( secondValue );
}


myFunction (); //works but no alert
myFunction ("Hello");// 1 alert
myFunction ("Hello", "World");// 2 alerts

as you see all three method calls work although it is declared with 2 arguments

---

JavaScript does not actually require you to pass all the parameters to a function. Or any parameters. Or, you can pass more parameters than the function names in it's signature.

If the function defines a parameter, obj, but you just call it like

otherfunction();

Then obj is just undefined.

---

There isn't any way to get a function signature in JavaScript. However, you can just pass any arguments you may need, and the function will ignore them if it doesn't need them. It won't cause an error.

---

You can get the list of arguments passed to your function regardless of what you put in your function signature by looking at the arguments local variable.

You can call a function with any number of arguments using the Function apply method.

So to create a wrapper function that passes all its arguments onto the wrapped function:

function myfunction() {
    otherfunction.apply(window, arguments);
}

Is this what you're trying to do?

(window is the value that this will be set to in the wrapped function; if you don't have a specific object you're calling a method on, the global window object is normally used.)

---

you can use Functions as

function printOut(func,msg){
 return func(msg)
}

function test1(msg){
return "am test1 " + msg;

}

function test2(msg){
return "am test2 " +msg;
}


console.log(printOut(test2,"Function !!!"));