“正则表达式 练习：验证邮箱地址”的版本间的差异

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（未显示同一用户的3个中间版本）
第19行： 第19行：
 
     public static void main(String[] args) {
 
     public static void main(String[] args) {
  
−
         String regex = "[a-zA-Z0-9_\\-]+@((\\w+\\.))+\\w+";
+
         String regex = "[\\w-]+@([a-zA-Z]+\\.)+[a-zA-Z]+";
  
 
         Homework01 work = new Homework01();
 
         Homework01 work = new Homework01();
  
−
         System.out.println("work.test1(regex) success:" + work.test1(regex));
+
        String content = "jihongchang@jihongchang.top";
 +
 
 +
        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));
 +
 
 +
        content = "jihongchang@";
 +
 
 +
         System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));
  
−
         System.out.println("work.test2(regex) success:" + work.test2(regex));
+
         content = "jihongchang@jihongchang";
  
−
         System.out.println("work.test3(regex) success:" + work.test3(regex));
+
         System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));
  
−
         System.out.println("work.test4(regex) success:" + work.test4(regex));
+
        content = "jihongchang@jihongchang.";
 +
 
 +
        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));
 +
 
 +
        content = "ji_hong-chang@jihongchang.top";
 +
 
 +
         System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));
 +
 
 +
        content = "ji_hong-chang@jihongchang.@jihongchang.top";
 +
 
 +
        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));
  
 
     }
 
     }
第63行： 第79行：
  
 
         return !content.matches(regex);
 
         return !content.matches(regex);
 +
 +
    }
 +
 +
    public boolean test5(String regex) {
 +
 +
        String content = "ji_hong-chang@jihongchang.top";
 +
 +
        return content.matches(regex);
 +
 +
    }
 +
 +
    public boolean test6(String regex) {
 +
 +
        String content = "ji_hong-chang@jihongchang.@jihongchang.top";
 +
 +
        return content.matches(regex);
  
 
     }
 
     }
第68行： 第100行：
 
}
 
}
 
</syntaxhighlight><syntaxhighlight lang="console">
 
</syntaxhighlight><syntaxhighlight lang="console">
−
work.test1(regex) success:true
+
"jihongchang@jihongchang.top".matches(regex):true  
−
work.test2(regex) success:true
+
"jihongchang@".matches(regex):false
−
work.test3(regex) success:true
+
"jihongchang@jihongchang".matches(regex):false
−
work.test4(regex) success:true
+
"jihongchang@jihongchang.".matches(regex):false
−
</syntaxhighlight>
+
"ji_hong-chang@jihongchang.top".matches(regex):true  
 +
"ji_hong-chang@jihongchang.@jihongchang.top".matches(regex):false
 +
</syntaxhighlight>注意：String matches 是整体匹配

2022年11月22日 (二) 07:01的最新版本

https://www.bilibili.com/video/BV1Eq4y1E79W?p=24

验证电子邮件格式是否合法

规定电子邮件规则为：

  1. 只能有一个@
  2. @前面是用户名，可以是 a-z、A-Z、0-9、 _（下划线）、-（减号、中划线）字符
  3. @后面是域名，并且域名只能是英文字母，比如 sohu.com 或者 tsinghua.org.cn

写出对应的正则表达式，验证输入的字符串是否满足规则



自己实现的

public class Homework01 {

    public static void main(String[] args) {

        String regex = "[\\w-]+@([a-zA-Z]+\\.)+[a-zA-Z]+";

        Homework01 work = new Homework01();

        String content = "jihongchang@jihongchang.top";

        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));

        content = "jihongchang@";

        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));

        content = "jihongchang@jihongchang";

        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));

        content = "jihongchang@jihongchang.";

        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));

        content = "ji_hong-chang@jihongchang.top";

        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));

        content = "ji_hong-chang@jihongchang.@jihongchang.top";

        System.out.printf("\"%s\".matches(regex):%b \n", content, content.matches(regex));

    }


    public boolean test1(String regex) {

        String content = "jihongchang@jihongchang.top";

        return content.matches(regex);

    }

    public boolean test2(String regex) {

        String content = "jihongchang@";

        return !content.matches(regex);

    }

    public boolean test3(String regex) {

        String content = "jihongchang@jihongchang";

        return !content.matches(regex);

    }

    public boolean test4(String regex) {

        String content = "jihongchang@jihongchang.";

        return !content.matches(regex);

    }

    public boolean test5(String regex) {

        String content = "ji_hong-chang@jihongchang.top";

        return content.matches(regex);

    }

    public boolean test6(String regex) {

        String content = "ji_hong-chang@jihongchang.@jihongchang.top";

        return content.matches(regex);

    }

}

"jihongchang@jihongchang.top".matches(regex):true 
"jihongchang@".matches(regex):false 
"jihongchang@jihongchang".matches(regex):false 
"jihongchang@jihongchang.".matches(regex):false 
"ji_hong-chang@jihongchang.top".matches(regex):true 
"ji_hong-chang@jihongchang.@jihongchang.top".matches(regex):false

注意：String matches 是整体匹配

取自“https://www.jihongchang.top/index.php?title=正则表达式_练习：验证邮箱地址&oldid=3810”