call 和 apply 的用法

<script type="text/javascript">
    function call1() {
        this.addr = "china";
        this.getAddr = function () {
            return this.addr;
        }
    }
    function call2() {
        this.addr = "zhejiang";
        this.setAddr = function (addr) {
            this.addr = addr;            
        }
    }

    var a = new call1();
    var b = new call2();
    b.setAddr.call(a, "hangzhou");
    alert(a.getAddr());
</script>


<script type="text/javascript">
    function T1(a, b, c, d) {
        alert(a+b+c+d);
    }
    function T2(a,b,c,d) {
        T1.apply(this, [a,b,c,d]);
    }      
        T2("a","b",3,65);       
</script>