package com.hanqi1;import java.util.Random;public class Test {    public static void main(String[] args)    {        String str1 = "字符串常量";      //字符串用""   字符用''                String str2 = null;                str2 = new String();                str2 = new String("实例化字符串");                char[] c = new char[]{
   'a','b','c'};                str2 = new String(c);                str2 = "fhospdowqdjshf";                //字符集                         System.out.println("str2.length=" + str2.length());                System.out.println("str2=" + str2);                //查找字符或字符串        int in = str2.indexOf("bc");                System.out.println("bc ="+in);  //输出的结果为索引值                int la = str2.lastIndexOf("d");                System.out.println("d = "+la);                String newStr = str2.substring(5);                newStr = str2.substring(5,6);                System.out.println("substring()=" + newStr);                str2 = " abcdds ";                //去除前后空格        System.out.println("去空格 ="+ str2.trim()+"后面");        //查找替换        System.out.println("查找替换空格="+str2.replace("","") + "后面");                str2 = "abc,你好";                System.out.println("查找替换空格="+str2.replace("abc","张三") + "");                str2 = "abcde";                //判断字符串开始和结束        System.out.println("判断起始 = "+str2.startsWith("a"));                System.out.println("判断起始 = "+(str2.indexOf("abc")==0));            System.out.println("判断结束= "+str2.endsWith("de"));                        str1 = new String("abc");        str2 = new String("abc");                str2 = "ABC";                System.out.println("判断字符串是否相等="+ (str1 == str2)+"str1="+str1.toUpperCase() +"str2 = "+str2.toLowerCase());                        System.out.println("判断字符串是否相等="+ str1.equals(str2));                                str2 = "abc#def#ghr#xyz";                String[] array = str2.split("#");                for (int i = 0;i