javascript - js中 'function(event)'是什么意思

Question

我不知道'function(event)'这句话的意思

Event.add(apple,'click',function(event) {
    Event.stopPropagation(event);
});

参数'event'不是javascript的唯一关键字吗？

关键字可以作为某个函数的参数吗？

我理解以下代码的含义:

function(test) {
alert(test);
}

但是我不明白这个:

function(event)...

有人可以给我解释一下吗？

Answer 1

The event object is always passed to the handler and contains a lot of useful information what has happened.

Different types of events provide different properties. For example, the onclick event object contains:

• event.target - the reference to clicked element. IE uses event.srcElement instead.
• event.clientX / event.clientY - coordinates of the pointer at the moment of click.

Information about which button was clicked and other properties. Please visit this link.
It answers all your questions very simply

来源http://javascript.info/tutorial/obtaining-event-object

示例:

就像在 HTML 中你分配了这样的事件

<button onclick="alert(event)">See the event</button>

然后

function alert(event) {
    // event.type contains whether this event was invoked in the result of a click etc
    // event.target would contain the reference to the element which invoked this method/event
}