稍微记下jquery each方法利用了js的call和apply进行方法调用,看下《js权威指南》中的call和apply的用法:
function.call(thisobj, args...)
24.84.1.1. Arguments
thisobj
The object on which function is to be invoked. In the body of the function, thisobj becomes the value of the this keyword. If this argument is null, the global object is used.
args...
Any number of arguments, which will be passed as arguments to function.
当我们使用$('..').each(function(){..})时,实际是进行的调用是
for(var i = i;i<$('..').length;i++){
var val = $('..')[i];
//function中的this指向val,传入的参数为$('..')的索引和索引处的值
function.call(val,i,val);
}
function.call(thisobj, args...)
24.84.1.1. Arguments
thisobj
The object on which function is to be invoked. In the body of the function, thisobj becomes the value of the this keyword. If this argument is null, the global object is used.
args...
Any number of arguments, which will be passed as arguments to function.
当我们使用$('..').each(function(){..})时,实际是进行的调用是
for(var i = i;i<$('..').length;i++){
var val = $('..')[i];
//function中的this指向val,传入的参数为$('..')的索引和索引处的值
function.call(val,i,val);
}
本文深入解析了jQuery中each方法的工作原理及其内部实现机制,重点介绍了如何利用JavaScript的call和apply方法来改变函数调用中的this指向,使得each方法能够正确地遍历DOM元素集合。
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