1, the regular expression grouping function
-
Capture group which may be opened by the bracket numbered left to right. For example, in the expression ((A) (B (C))), there are four such groups:
1 ((A)(B(C)))
2 (A
3 (B(C))
4 (C)
Group zero always represents the entire expression.
public static void demo1() {
//叠词 快快乐乐,高高兴兴
/*String regex = "(.)\\1(.)\\2"; //\\1代表第一组又出现一次 \\2代表第二组又出现一次
System.out.println("快快乐乐".matches(regex));
System.out.println("快乐乐乐".matches(regex));
System.out.println("高高兴兴".matches(regex));
System.out.println("死啦死啦".matches(regex));*/
//叠词 死啦死啦,高兴高兴
String regex2 = "(..)\\1";
System.out.println("死啦死啦".matches(regex2));
System.out.println("高兴高兴".matches(regex2));
System.out.println("快快乐乐".matches(regex2));
}2, cutting
[1] Required: Please cut to fold word: "sdqqfgkkkhjppppkl";
[2] replace
-
Requirements: I ... I .... I want to ... I want to ... learn to learn .... .. .. compiled code compiled learn programming Cheng Cheng ........ journey
-
Restore string into: "I want to learn programming."
public static void main(String[] args) {
/*
* 需求：我我....我...我.要...要要...要学....学学..学.编..编编.编.程.程.程..程
将字符串还原成:“我要学编程”。
*/
String s = "我我....我...我.要...要要...要学....学学..学.编..编编.编.程.程.程..程";
String s2 = s.replaceAll("\\.+", "");
String s3 = s2.replaceAll("(.)\\1+", "$1"); //$1代表第一组中的内容
System.out.println(s3);
}
public static void demo2() {
//需求：请按照叠词切割： "sdqqfgkkkhjppppkl";
String s = "sdqqfgkkkhjppppkl";
String regex = "(.)\\1+"; //+代表第一组出现一次到多次
String[] arr = s.split(regex);
for (int i = 0; i < arr.length; i++) {
System.out.println(arr[i]);
}
}