1.体验
1.需求
验证QQ号是否合法，首位不能是0，长度6-20，必须纯数字
2.没有正则表达式
package cn.hdc.opp6.zhengzebiaodashi;public class Main1 {public static void main(String[] args) {System.out.println(checkQQ("2652110187"));}public static boolean checkQQ(String QQ) {if (QQ == null || QQ.charAt(0) == '0' || QQ.length() < 6 || QQ.length() > 20) {return false;}for (int i = 0; i < QQ.length(); i++) {if (QQ.charAt(i) < 48 || QQ.charAt(i) > 57) {return false;}}return true;}
}
3.使用正则表达式
package cn.hdc.opp6.zhengzebiaodashi;public class Main1 {public static void main(String[] args) {System.out.println(checkQQ1("2652110187"));}public static boolean checkQQ1(String QQ) {return QQ != null && QQ.matches("[1-9]\\d{5,19}");}
}
2.正则表达式
案例
package cn.hdc.opp6.ZhengZedemo;import java.util.Scanner;public class d1 {public static void main(String[] args) {checkPhone();}private static void checkPhone() {while (true) {System.out.println("请输入你的时间：");Scanner sc = new Scanner(System.in);String phone = sc.nextLine();
// if (phone.matches("[0-2]?[0-3]点[0-5]?[0-9]分[0-5]?[0-9]秒")) {if (phone.matches("([01]?[0-9]|2[0-3])点([0-5]?[0-9])分([0-5]?[0-9])秒")) {System.out.println(true);
// break;} else {System.out.println(false);}}/*while (true) {System.out.println("请输入你的邮箱：");Scanner sc = new Scanner(System.in);String phone = sc.nextLine();if (phone.matches("\\w{2,}@[a-zA-Z0-9]{2,20}(\\.\\w{2,10}){1,2}")) {System.out.println(true);break;} else {System.out.println(false);}}
*/
/*while (true) {System.out.println("请输入你的手机号：");Scanner sc = new Scanner(System.in);String phone = sc.nextLine();if (phone.matches("(1[3-9]\\d{9})|(0\\d{2,7}-?[1-9]\\d{4,19})")) {System.out.println(true);break;} else {System.out.println(false);}}
*/}}
爬取信息
package cn.hdc.opp6.ZhengZeSelect;import java.util.regex.Matcher;
import java.util.regex.Pattern;public class Main {public static void main(String[] args) {queryInfo();}private static void queryInfo() {String str ="来黑马程序员学习Java\n" +"电话:18512516758，18512508907\n" +"或者联系邮箱: boniu@itcast.cn\n" +"座机电话:01036517895，010-98951256\n" +"邮箱:bozai@itcast.cn\n" +"邮箱2:dlei0009@163.com\n" +"热线电话:400-618-9090，400-618-4000\n" +"4006184000，4006189090";//爬取电话String regex ="(1[3-9]\\d{9})|" +//爬取邮箱"(\\w{1,}@\\w{2,10}\\.(\\w{2,10}){1,2})|" +//爬取座机号码"010[- ]?\\d{3,8}|" +//爬取热线"400[- ]?\\d{3,8}[- ]?\\d{3,8}";Pattern p = Pattern.compile(regex);Matcher m = p.matcher(str);while (m.find()) {System.out.println(m.group());}}
}
搜索、替换内容
private static void queryUserName() {String str = "来黑马程序员学习Java\n" +"电话:18512516758，18512508907\n" +"或者联系邮箱: boniu@itcast.cn\n" +"座机电话:01036517895，010-98951256\n" +"邮箱:bozai@itcast.cn\n" +"邮箱2:dlei0009@163.com\n" +"热线电话:400-618-9090，400-618-4000\n" +"4006184000，4006189090";String regex = "\\w{1,}@\\w{2,10}(\\.\\w{2,10}){1,2}";Pattern p = Pattern.compile(regex);Matcher m = p.matcher(str);while (m.find()) {String res = m.group().split("@")[0];System.out.println(res);}}package cn.hdc.opp6.ZhengZeSelect;import java.util.Arrays;public class ReplaceAndSplit {public static void main(String[] args) {//1、public String replaceAll(String regex，String newstr):按照正则表达式匹配的内容进行替换// 需求1:请把 古力娜扎ai8888迪丽热巴999aa5566马尔扎哈fbbfsfs42425卡尔扎巴，中间的非中文字符替换成“_"String str = "古力娜扎ai8888迪丽热巴999aa5566马尔扎哈fbbfsfs42425卡尔扎巴";String regex = "\\w+";System.out.println(str.replaceAll(regex, "-"));// 需求2(拓展):某语音系统，收到一个口吃的人说的 "我我我喜欢编编编编编编编编编编编编程程程!"，需要优化成 "我喜欢编程!"String str1 = "我我我喜欢编编编编编编编编编编编编程程程!";String reges1 = "(.)\\1+";/*** (.)代表任意一组，.代表匹配任意字符* \\1 :为这个组声明一个组号：1号(一定用\\1，这是规定好的)* + :声明必须是重复的字：一次以上* $1 :取到第一组代表的那个重复的字*/System.out.println(str1.replaceAll(reges1, "$1"));// 2、public string[] split(String regex):按照正则表达式匹配的内容进行分割字符串，反回一个字符串数组。//需求1:请把古力娜扎ai8888迪丽热巴999aa5566马尔扎哈fbbfsfs42425卡尔扎巴，中的人名获取出来。String str2 = "古力娜扎ai8888迪丽热巴999aa5566马尔扎哈fbbfsfs42425卡尔扎巴";String regex2 = "\\w+";System.out.println(Arrays.toString(str2.split(regex2)));}
}
