说明jquery的bind和on的区别
As of jQuery 1.7, the .on() method is the preferred method for attaching event h...
As of jQuery 1.7, the .on() method is the preferred method for attaching event h...
通过这种方式创建一个值为undefined的变量。 传window是出于性能考虑,js寻找一个变量是沿着作用域链逐级往上找的,把window变为函数内部的局部变...