闭包1-3

HTML

<button>0</button> 
<button>1</button> 
<button>2</button> 
<button>3</button>

JavaScript

var button = document.getElementsByTagName("button");
// 也可以这样

var addEventListener = function(nodes){
    var i;

    for(i = 0; i < nodes.length; i++){
        nodes[i].onclick = (function(anotherI){
            return function(){
                alert(anotherI);
            };
        })(i);
    }
}

addEventListener(button);