Tips for binding multiple JavaScript functions to the OnLoad event handler

One, the OnLoad event occurs condition

The user enters the page and all elements of the page are loaded. If you add a JavaScript function at the initial position of the page, the DOM is incomplete because the document is not loaded, which can cause the function to execute incorrectly or not achieve the effect we want.

Two, bind multiple functions to the OnLoad event

1, first show a wrong approach

1 window.onload = firstfunction; 2 window.onload = secondfunction;

During the actual execution, only the last function is executed, because each event handler can only bind one instruction.

2, use an anonymous function

1 function ()2{3    firstfunction (); 4     secondfunction (); 5 }

3, a general-purpose solution

The function name is Addloadevent, which is written by Simon Willision, which is the name of the function that needs to be executed when the page finishes executing.

1 functionaddloadevent (func)2 {3     varOldonload =window.onload;4     if(typeofWindow.onload! = ' function ')5     {6Window.onload =func;7     }8     Else9     {TenWindow.onload =function() One         { A oldonload (); - func (); -         } the     } -}

The advantage of this function is that no matter how many functions need to be executed, I can just add a single statement to get it done without having to modify the previous code.

1     addloadfunction (firstfunction); 2     Addloadfunction (secondfunction);

Tips for binding multiple JavaScript functions to the OnLoad event handler