SOURCE

    document.write("获取数组的长度----------------------------<br/>");
		 var a=[1,2,3,4,5];
         document.write(a+"<br/>");
		document.write(a.length+"<br/>");
	document.write("获取数组的1-2号元素----------------------------<br/>");
		document.write(a.slice(0,2)+"<br/>");
	document.write("往数组头添加元素----------------------------<br/>");
		document.write(a.unshift(-2,-1,0)+"<br/>");
	document.write("往数组尾部添加元素----------------------------<br/>");
		document.write(a.push(6,7,8)+"<br/>");
	document.write("删除数组的第一个元素----------------------------<br/>");
		document.write(a.shift()+"<br/>");
	document.write("删除数组的最后一个元素----------------------------<br/>"); 
		document.write(a.pop()+"<br/>");


        function upCompare(left, right) {
    if (left - right > 0) {
        return 1;
    }

    if (left - right == 0) {
        return 0;
    }

    if (left - right < 0) {
        return -1;
    }

}
function downCompare(left, right) {
    if (left - right > 0) {
        return -1;
    }

    if (left - right == 0) {
        return 0;
    }

    if (left - right < 0) {
        return 1;
    }

} 

        var s="绿叶学习网";
		s=s.split("").join("><");
		var s1=s.split("");
		s1.unshift("<");
		s1.push(">");
		s=s1.join("");
		document.write(s);