Learn jquery from scratch: how to use callback functions_jquery

In C-like languages, it is usually passed by function pointer/reference.

jquery also provides a similar callback function mechanism. But it's still worth mentioning how to pass the callback function correctly.

1. Callback without parameters

Copy code The code is as follows:

$.get('myhtmlpage.html', myCallBack) ;

Where myCallBack is the function name. Functions are the basis of JavaScript. Can be passed as a reference variable.

2. Callback with parameters

Naturally, according to past experience, we will think that the callback with parameters looks like the following:

Copy code The code is as follows:

$.get('myhtmlpage.html', myCallBack( param1, param2));

But this won’t work properly. myCallBack(param1, param2) will be executed when this statement is called, not after.

The following syntax is correct:

Copy code The code is as follows:

$.get('myhtmlpage.html', function( ){
myCallBack(param1, param2);
});

In this way, the callback function is passed as a function pointer and will be executed after the get operation is completed.