JavaScript attachevent and AddEventListener using methods _javascript Tips

Attachevent Method Button onclick
AddEventListener Method Button click
The rationale for the use of the two is that it is not the same as the priority of execution, as the following examples explain:
Attachevent method, attaching additional handling events for an event. (Mozilla series not supported)
AddEventListener Method for Mozilla series
Example:
Java code

Copy Code code as follows:

document.getElementById ("btn"). onclick = method1;
document.getElementById ("btn"). onclick = Method2;
document.getElementById ("btn"). onclick = method3;

If you write this, then only MEDHOT3 will be executed.
Written in this way:
Java code:

Copy Code code as follows:

var btn1obj = document.getElementById ("btn1");
Object.attachevent (event,function);
Btn1obj.attachevent ("onclick", method1);
Btn1obj.attachevent ("onclick", method2);
Btn1obj.attachevent ("onclick", method3);

The order of execution is method3->method2->method1
If it is a Mozilla series, this method is not supported and requires the use of AddEventListener
Java code:

Copy Code code as follows:

var btn1obj = document.getElementById ("btn1");
Element.addeventlistener (type,listener,usecapture);
Btn1obj.addeventlistener ("click", Method1,false);
Btn1obj.addeventlistener ("click", Method2,false);
Btn1obj.addeventlistener ("click", Method3,false);

The order of execution is method1->method2->method3
Use instance:
1. Java code:

Copy Code code as follows:

var el = editform_document.body;
First get the object, Editform_document is an IFRAME
if (El.addeventlistener) ... {
El.addeventlistener (' Click ', Kinddisablemenu, false);
else if (el.attachevent) ... {
El.attachevent (' onclick ', kinddisablemenu);
}

2. Java code:

Copy Code code as follows:

if (Window.addeventlistener) {
Window.addeventlistener (' Load ', _uco, false);
else if (window.attachevent) {
Window.attachevent (' onload ', _uco);
}