Summary of various calling methods of anonymous functions in Javascript_javascript skills

There are many ways to define functions in Javascript, and function literals are one of them. For example, var fun = function(){}, if function is not assigned to fun, then it is an anonymous function. Okay, let's see how the anonymous function is called.

Method 1, call the function and get the return value. The coercion operator causes the function call to execute

Copy code The code is as follows:

(function (x,y){
alert(x y);
return x y;
}(3,4));

Method 2, call the function and get Return value. Force the function to be executed directly and then return a reference. The reference is then called and executed

Copy the code The code is as follows:

(function(x,y){
alert(x y);
return x y;
})(3,4);

This kind of This method is also a popular calling method used by many libraries, such as jQuery and Mootools

Method 3, use void

Copy the code The code is as follows:

void function(x) {
x = x-1;
alert(x);
}(9);

Method 4, use - / Operator

Copy code The code is as follows:

-function(x,y ){
alert(x y);
return x y;
}(3,4);

function(x,y){
alert(x y);
return x y;
}(3,4);

--function(x,y){
alert(x y);
return x y;
}(3,4 );

function(x,y){
alert(x y);
return x y;
}(3,4);

Method 5, use the tilde (~)

Copy the code The code is as follows:

~function(x, y) {
alert(x y);
return x y;
}(3, 4);

Finally look at the wrong calling method

Copy code The code is as follows:

function(x,y){
alert(x y );
return x y;
}(3,4);