[Some information relates to pre-released product which may be substantially modified before it's commercially released. Microsoft makes no warranties, express or implied, with respect to the information provided here.] [涉及某信息预发布的版本可能在它的商业版本大幅修改.对于这里…
一,三者共同点 js中的apply,call,bind是对于初学者比较难的概念之一,比如说我..参考几篇文章之后,统一来讲, 1.这三个函数都属于Function.prototype下面的方法,如下图所示.从而可以被每一个函数实例所调用. 2.他们的作用都是改变函数的执行上下文.举个例子: var a=1; function printA(){ console.log(this.a); } var obj={a:2}; printA();//相当于window.printA(),此时this指向…
我们常常在执行 httpd –k restart 重启Apache时报错提示: (OS 10048)通常每个套接字地址(协议/网络地址/端口)只允许使用一次. : AH00072: make_sock: could not bind to address 0.0.0.0:80AH00451: no listening sockets available, shutting downAH00015: Unable to open logs 如图: 解决方法: 直接干掉一个httpd.exe然后再…
最近用js的类写东西,发现一个无比蛋疼的事,那就是封装的类方法中的this指针经常会改变指向,失去上下文,导致程序错误或崩溃. 比如: function Obj(){ this.type = "obj";}Obj.prototype = { show : function (){ etTimeout(function (){ console.log(this.type); },300) } var obj = new Obj();obj.show(); //undefined 所幸伟…
if (!Function.prototype.bind) { Function.prototype.bind = function(oThis) { if (typeof this !== 'function') { throw new TypeError('What is trying to be bound is not callable'); } var aArgs = Array.prototype.slice.call(arguments, 1), fToBind = this, f…
