<script>

        var stringObject = new String("hello world");

        document.write("字符：" + stringObject + "<br>");

        document.write("每个字符也仍然算一个字符：" + stringObject.length + "<br>");

        document.write("以单字符字符串的形式返回给定位置的那个字符：" + stringObject.charAt(1) + "<br>");

        document.write("以单字符字符串的形式返回字符编码：" + stringObject.charCodeAt(1) + "<br>");

        //获取A_Z的大写字符

        var A_Z = [];

        for (var i = 65; i < 91; i++) {

            var strA = String.fromCharCode(i);

            A_Z.push(strA);

        }

        console.log(A_Z);

        document.write("输出26个大写字符：" + A_Z + "<br>");

        var stringValue = "hello ";

        var result = stringValue.concat("world");

        document.write("stringValue拼接的原始数据:" + stringValue + ",使用concat用于将一或多个字符拼接起来,返回拼接得到的新字符串：" + result + "<br>");

        document.write("原始的stringValue的值保持不变：" + stringValue + "<br>");

        var stringValue = " hello world ";

        var trimmedStringValue = stringValue.trim();  //删除前置及后缀的所有空格

        document.write("删除前置及后缀的所有空格：" + trimmedStringValue + "<br>");

        var trimLeftmedStringValue = stringValue.trimLeft();  //删除开头的空格

        document.write("删除前置的空格：" + trimLeftmedStringValue + "<br>");

        var trimRightmedStringValue = stringValue.trimRight();  //删除后缀的空格

        document.write("删除后缀的空格：" + trimRightmedStringValue + "<br>");

        //字符大小写转换方法

        var stringtoLocalUpperCase = stringValue.toLocaleUpperCase();

        var stringtoUpperCase = stringValue.toUpperCase();

        document.write("大写转换：" + stringtoLocalUpperCase + "<br>");

        var stringtoLocaleLowerCase = stringValue.toLocaleLowerCase();

        var stringtoLowerCase = stringValue.toLowerCase();

        document.write("小写转换：" + stringtoLocaleLowerCase + "<br>");

        var uri = "http://www.wrox.com/illegalvalue.htm#start";

        //alert(encodeURI(uri));

        //"http%3A%2F%2Fwww.wrox.com%2Fillegal%20value.htm%23start"

        //alert(encodeURIComponent(uri));

        document.write("加密encodeURI：" + encodeURI(uri) + "<br>");

        document.write("加密encodeURIComponent：" + encodeURIComponent(uri) + "<br>");

        //Math对象

        var max = Math.max(3, 54, 32, 16);

        document.write("max的最大值：" + max + "<br>");

        var min = Math.min(3, 54, 32, 16);

        document.write("min的最小值：" + min + "<br>");

        //找数组的最大或者最小值，可以调用apply使用

        var valueArray = [1, 2, 3, 4, 5, 6, 7, 8];

        var maxApply = Math.max.apply(Math, valueArray);

        var minApply = Math.min.apply(Math, valueArray);

        document.write("获取数组的最大值：" + maxApply + "<br>");

        document.write("获取数组的最小值：" + minApply + "<br>");

        /*舍入方法

            Math.ceil()     执行向上舍入,始终将数值向上舍入为最接近的整数

            Math.floor()    执行向下舍入,始终将数值向下舍入为最接近的整数

            Math.round()    执行标准舍入,即总是将数值四舍五入为最接近的整数

        */

        document.write("Math.ceil() 执行向上舍入：" + Math.ceil(25.9) + "<br>");

        document.write("Math.floor()执行向下舍入：" + Math.floor(25.9) + "<br>");

        document.write("Math.round()执行标准舍入：" + Math.round(25.1) + "<br>");

        //随机1-10的数值

        var num = Math.floor(Math.random() * 10 + 1);

        //随机2-10的数值

        var numtwo = Math.floor(Math.random() * 9 + 2);

        function selectFrom(lowerValue, upperValue) {

            var choices = upperValue - lowerValue + 1;

            return Math.floor(Math.random()*choices+lowerValue);

        }

        var numForm = selectFrom(2, 10);

        //alert(numForm); //介于2和10之间的一个数值,总值和第一个出现的值

        document.write("介于2和10之间的一个数值：" + numForm + "<br>");

        var colors = ["red", "green", "blue", "yellow", "black", "purple", "brown"];

        var color = colors[selectFrom(0, colors.length - 1)];

        document.write("取随机数组的颜色：" + color + "<br>");

    </script>