<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <script type="text/javascript">

        function testDate(){
            /**
             * 测试Date对象
             */
            var date = new Date();
            console.log(date.getFullYear());
            console.log(date.getYear());
            console.log(date.getMonth());
            console.log(date.getDay());
            console.log(date.getDate());
            console.log(date.getHours());
            console.log(date.getMinutes());
            console.log(date.getSeconds());
            console.log(date.getMilliseconds());
        }

        function testString(){
            var s = "this is a STRING test";
            //穿件一个锚点 <a name="is">this is a string test</a>
            //document.write(s.anchor("is"));
            console.log(s.anchor("is"));
            console.log(s.charAt(2));
            console.log(s[2]);
            console.log(s.charCodeAt(2));

            console.log(s.concat(",this","is "));
            //返回的是  第一个与它匹配的字符串的位置
            console.log(s.indexOf("is",8))  //第二个参数  表示  查找的其实位置

            console.log(s.replace("is",function (){
                return "tttt";      //用函数处理  返回值
            }));

            console.log(s.substr(1,2)); //长度   包含末尾
            console.log(s.substring(1,2));  //位置  不包含末尾

            console.log(s.toLowerCase());
            console.log(s.toUpperCase());

            //字符串可以当作数组使用
            s[2] = "tttt";
            console.log(s);

            for(var i in s){
                console.log(s[i]);
            }
        }

        function testMath(){
            console.log(Math.abs("-10"));
            console.log(Math.ceil(-1.2));
            console.log(Math.floor(-1.2));

            console.log(Math.max(1,2,.43,123,21,3,1,4,2,5,7,8));

            console.log(Math.min(1,2,.43,123,21,3,1,4,2,5,7,8))

            //在计算金融的时候  一定要适当的将大单位换成小单位计算
            var n1 = 0.2-0.1;
            var n2 = 0.3-0.2;
            console.log(n1===n2);

        }

    </script>
</head>
<body>
<input type="button" onclick="testDate()" value="date">
<input type="button" onclick="testString()" value="string">
<input type="button" onclick="testMath()" value="math">
</body>
</html>