有人有在JavaScript中重写alert()函数的经验吗?

哪些浏览器支持这个功能? 哪些浏览器版本支持此功能? 重写函数的危险是什么?


当前回答

正如在许多其他答案中所述,您可以使用

window.alert = null

or

window.alert = function(){}

然而,这并不一定会覆盖Window构造函数原型上的函数(注意大写的W),所以黑客仍然可以输入:

Window.prototype.alert.apply(window, ["You were hacked!"]);

因此,你还需要重写该函数:

Window.prototype.alert = null

or

Window.prototype.alert = function(){}

其他回答

我认为每个Javascript实现都将支持这一点,并且这样做不会有任何危险。通常用HTML/CSS代替简单的os风格的警告框。这样做意味着您不必更改现有的代码!这一事实使得Javascript非常棒。

我做的一个快速破解来找到警报来自哪里,是去控制台,然后输入这个

function alert(message) { 
  console.info(message);
  debugger;
} 

When it comes to js browser functions window.alert is pre-eminent and most well known, people who don't know js know alert() -- rest assured it is supported in all browsers in use today and your code snippet is as well. However, I wouldn't override (well this is more like refactoring rather than override in the OOP sense) alert() for a particular use case as yours because when you actually need to use alert() with no template, and you probably will, then you'll need another non-alert function to do so.

我重写alert()函数的经验是,我们曾经使用它来“破解”JavaScript库的试用版,该库在每次提醒时都显示“请注册!”的提示屏幕。

我们刚刚定义了自己的alert()函数,瞧。

这只是为了测试,我们后来买了完整版,所以这里没有什么不道德的事情;-)

Ladislav。 对于IE8,你可以像这样重新定义alert()

/** 
 * Definition of global attached to window properties <br/>
 */ 
    (function() {
      nalert = window.alert;
      Type = {
          native: 'native',
          custom: 'custom'
      };
    })();

/**
 * Factory method for calling alert(). 
 * It will be call a native alert() or a custom redefined alert() by a Type param.
 * This defeinition need for IE
 */ 
    (function(proxy) {

          proxy.alert = function () {
          var message = (!arguments[0]) ? 'null': arguments[0];
          var type = (!arguments[1]) ? '': arguments[1];

          if(type && type == 'native') {
           nalert(message);
          }
          else {
               document.write('<h1>I am redefiend alert()<br/>Alert say: '+message+'</h1>');
          }     
      };
   })(this);

并调用as

alert('Hello, hacker!');
nalert('I am native alert');
alert('Hello, user!', Type.custom);