js_in_object2.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<!--Array数组对象
常用方法:
concat():合并数组
sort():排序
push():末尾追加元素,返回的是元素的个数
reverse():数组元素翻转
-->


<!--Math对象
该对象执行常见的算数任务
常用方法:
round():四舍五入的方法,保留的是整数部分
random():或取随机数,获取从0到1的随机小数,可以根据某些运算进行区间的改变
max():返回最大值
min():返回最小值
abs():返回绝对值

-->


<script>
    function Sort(a,b){
        return b-a;
    }
    var a = ["hello","world"];
    var b = ["year","day"];
    var c = a.concat(b);
    var d = ["a","z","g","i","b"];
    document.write(c + "<br/>");
    //经测试,下面这一行的写法只适用于数字排序,sort对于字符串默认排序是升序
    document.write(d.sort(function (a, b) {
                return a-b;
            }) + "<br/>");
    document.write(b.push(a) + "<br/>");
    document.write(b + "<br/>");
    document.write(d.reverse());
</script>

<script>
    document.write(Math.round(2.56) + "<br/>");
    document.write(Math.round(2.5) + "<br/>");
    document.write(Math.random()*10 + "<br/>");
    document.write(parseInt(Math.random()*10) + "<br/>");
    document.write(Math.max(10,20,89,23,46,7) + "<br/>");
    document.write(Math.min(10,20,89,23,46,7) + "<br/>");
    document.write(Math.abs(-2783) + "<br/>");
</script>
</body>
</html>