Judging whether the string is a legal IP is almost a must-test for the school recruitment interview every year
Next, I will use Java code to analyze this test site
/**
* FILENAME : Judge
* Author : HangLi
* Data : 2020/10/27 9:03
* Description : judge ip
**/
public class Judge {
public static void main(String[] args){
// 定义正则表达式
String regex = "\\w+@\\w+(\\.\\w{2,3})*\\.\\w{2,3}";
String str1 = "aaa@";
String str2 = "aaaaaaa";
String str3 = "[email protected]";
// 判断字符串变量是否与正则表达式匹配
if (str1.matches(regex)){
System.out.println(str1+"是一个合法的E-mail地址");
}
if (str2.matches(regex)){
System.out.println(str2+"是一个合法的E-mail地址");
}
if (str3.matches(regex)){
System.out.println(str3+"是一个合法的E-mail地址");
}
}
}
The most important part of this part is to examine the understanding of regular expressions
