java 字符串 实例

public class SameFirstName {
    
    public static void main(String[] args) {
        String[] ns = {"张三", "李四", "王五", "赵六", "周七", "王哲", "白浩", "贾蓉", "慕容阿三", "黄蓉"};
        for (int i= 0; i < ns.length; i++) {
            for (int j = i+1; j < ns.length; j++) {
//                结束相同的打印出来
                if (ns[i].charAt(ns[i].length()-1) == ns[j].charAt(ns[j].length()-1) ) {
                    System.out.println("以【"+ns[i].charAt(ns[i].length()-1)+"】结束的有："+ns[i]+" "+ns[j] );
                }
            }
        }
    }
}

import java.util.Scanner;

public class PictureType {

    public static void main(String[] args) {
        String[] pic = {"abc.jpg", "d.gif", "ef.png", "hijk.jpg", "lmn.gif", "opqrst.jpg"};
        String[] suffixs = {".jpg", ".gif", ".png"};
        System.out.println("注：1－.jpg　2－.gif　3－.png");

        Scanner sc = new Scanner(System.in);
        do {
            System.out.println("\n请输入要图片格式的编号：");
            int x = sc.nextInt();
            if (x > 3) {
                System.out.println("输入错误！");
            } else if (x == 0) {
                break;
            } else {
                String suffix = suffixs[x - 1];
                System.out.println("以【" + suffix + "】结尾的有：");
                for (int i = 0; i < pic.length; i++) {
                    if (pic[i].endsWith(suffix)) {
                        System.out.print(pic[i] + " ");
                    }
                }
            }

        } while (true);
    }
}

import java.util.Locale;
import java.util.Scanner;

public class ReserveStr {
    public static void main(String[] args) {
        Scanner sc =new Scanner(System.in);
        String str = sc.next();
        System.out.println("您输入的内容为："+str);

        char[] c = str.toCharArray();
        System.out.println("转为数组：");
        for (char i:c) {
            System.out.print(i+" ");
        }
        sc.close();
    }
}

public class PhoneNum {
 
    public static void main(String[] args) {
        String[] numb = {"13677554103", "043182956123", "04326168799", "13004319255", "13394251304", "17763258893"};
        System.out.println("含0431的号码有：");
        for (String item :numb
             ) {
            if (item.indexOf("0431") != -1) {
                System.out.println(item+"。长度为："+item.length()+"；起始数字为："+item.charAt(0)+"，是否以1开头："+item.startsWith("1")
                        +";末位数字为："+item.charAt((item.length()-1))+",是否以3开头："+item.endsWith("3"));
            }

            if (item.contains("0431")) {
                System.out.println(item+"。长度为："+item.length()+"；起始数字为："+item.charAt(0)+"，是否以1开头："+item.startsWith("1")
                        +";末位数字为："+item.charAt((item.length()-1))+",是否以3开头："+item.endsWith("3"));
            }

        }

    }
}

public class TelphoneSub {
  
    public static void main(String[] args) {
        String pn = "18600001234";// 电话号
        System.out.println("手机号为："+pn);
        System.out.println("前3位：" + pn.substring(0,3));// 输出前3位
        System.out.println("中间4位：" + pn.substring(3,7));// 输出中间4位
        String pn2= pn.replace("0000","****");
        System.out.println("中间4位替换为*后："+pn2);
        String[] c = pn.split("0");
        System.out.println("按0分隔手机号：");
        for (int i = 0; i <c.length ; i++) {
            System.out.print(c[i]+"-");
        }     
    }
}

import javax.jws.soap.SOAPBinding;
import java.util.Scanner;

public class Ticket {
    public static void main(String[] args) {

        String t = "", z = "", st = "", ed = "", dur = "";
        String[][] trains = {
                {"车次  ", "出发站-到达站", "出发时间", "到达时间", "历时"},
                {"T40  ", "长春-北京", "00:12", "12:20", "12:08"},
                {"T298 ", "长春-北京", "00:06", "10:50", "10:44"},
                {"Z158 ", "长春-北京", "12:48", "21:06", "08:18"},
                {"K1084", "长春-北京", "12:39", "02:16", "13:37"}
        };

//        输出车次信息
        for (int i = 0; i < trains.length; i++) {
            for (int j = 0; j < trains[i].length; j++) {
                System.out.print(trains[i][j] + "\t");
            }
            System.out.println();
        }


        Scanner sc = new Scanner(System.in);
        do {
            System.out.println("输入购买的车次");
            String train = sc.next();

            if (train.equals("0")) {
                System.out.println("结束买票，再见~");
                break;
            } else {
                for (int i = 0; i < trains.length; i++) {
                    t = trains[i][0].trim();//为了打印整齐，添加了空格，判断前需通过.trim()去掉空格
                    z = trains[i][1];
                    st = trains[i][2];
                    ed = trains[i][3];
                    dur = trains[i][4];
                    
                    if (train.equals(t)) //判断输入的车次同列表中的车次是否一致
                    {
                        System.out.println("您购买的车次为：" + t + "，" + z + "。于" + st + "出发，将于" + ed + "到达，历时：" + dur + "。");
                    }
                }
            }
        } while (true);
        sc.close();
    }
}

import java.util.Scanner;

public class EmployeeEntry { // 创建一个HereMachine类

    public static void main(String[] args) {
        String name = "张三三、李四四、王五五、赵六六"; // 初始化一个String类型的变量names
        System.out.println("原记录："+name);
//        替换一个名字，注替换后 原字符串内容不变，将生成新字符串
        String names = name.replace("李四四","李思思");
        System.out.println("替换后："+names);

        StringBuffer sb = new StringBuffer(names);
        System.out.println("原记录："+sb);
        sb.replace(0,3,"张三丰");
        System.out.println("替换后："+sb);

//        将每个名字第二位替换为*
        int[] index = {1,5,9,13};
        for (int i:index
             ) {
            sb.setCharAt(i,'*');
        }
        System.out.println("加密后："+sb);

//        录入新员工，排第一，末位删除
        Scanner sc = new Scanner(System.in);
        do {
            System.out.println("录入新人名：");
            String nn = sc.next();
            if (nn.equals("0")) {
                System.out.println("over");
                break;
            }else {
                sb.insert(0,nn+"、");
                System.out.println("新人后："+sb);
                sb.delete((sb.length()-4),(sb.length()));
                System.out.println("精简后："+sb);
            }
        }while (true);
        sc.close();
    }
}

import java.util.Scanner;

public class ScreenPhoneNum {
 
    public static void main(String[] args) {
//        替换手机中间4位
        String num = "13298762349";
        StringBuffer n = new StringBuffer(num);
        n.replace(3,7,"****");
        System.out.println(n);
    }
}

public class IPAddress {
    public static void main(String[] args) {
//        输出该IP地址的网络号码和本地计算机号码
        String ip = "192.168.1.147";
        int pt = ip.lastIndexOf('.');
        System.out.println("网络地址："+ip.substring(0,pt));
        System.out.println("本地地址："+ip.substring(pt+1,ip.length()));
    }
}