javascript中arguments的应用——不定项传参求和

<script type="text/javascript">
window.onload=function(){
function sum(){
var result=null;
for(var i=0; i<arguments.length;i++){
result+=arguments[i];
}
return result;
}
alert(sum(1,2));//sum中参数两个
alert(sum(1,2,3,555,888,666,333,555,777)); //sum中参数任意个
}
</script>