通过arguments对象实现动态参数

<script type="text/javascript">
		function sum()
		{
			var n = 0;
			for(var i = 0; i < arguments.length; i++)
			{
				n += arguments[i];
			}
			return n;
		}

		alert(sum(1,2,3));//6
		alert(sum(-1,2));//1
</script>

 

可以通过Function类建立函数，语法如下：

var funName = new Function(arg1,arg2,...,argN, functionBody);

<script type="text/javascript">
		var sum = new Function("n1","n2", "return n1+n2");
		//参数和函数体都必须加引号
		alert(sum(1,2));
</script>