regular expression

The basic content

[a-z] matching […] All characters in
[^a-b] Match except […] All the characters of the characters in
[\s\S] Match all .\s Is to match all blanks , Including line breaks ,\S Not blank , Including line breaks .
\w Match the letter 、 Numbers 、 Underline . Equivalent to [A-Za-z0-9_]
. All contents
\d Means match number
\d\d\d It means matching three consecutive numbers , If it's continuous , Then disconnect the match
\d{3} ditto
(\d\d){3} Express 6 Time Do not use parentheses to indicate 4 Time

\d{3,6} least 3 Time , most 6 Time
\d{3,} least 3 Time , There is no upper limit

When matching, it defaults to greedy mode , The more matches, the better
Add one in the back ？ Non greedy model

SYN?NN ？ The front one N It can appear once or 0 Time
SYN*NN * The front one N Can appear 0 1 2 3…
SYN+NN + Front N appear 1 2 3 4 5 …

a\d?b ab There is 0 perhaps 1 A digital

^ Matches where the string starts ^a Begin to match a
$ Match where the string ends a$ End match a

\b Matches a word boundary

toknnan\b
A single letter , The characters in front of and behind are not all \w

([a-z]{2})\1 Match repeat such as gogo
above \1 It can also be called back reference
Reference the string that the group has captured
(?:Expression) Non capturing group Do not occupy memory

m.group() Method You can group when querying 1 2 3 Represents that the front expression is different （） What's in it

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/** @Author ToknNan */

public class Test {
    

    public void testMatch1() {
    

        String s1 = "sss15831asdasdasd7762461";
        String lamba = "\\w+";
        // Expression object 
        Pattern p = Pattern.compile(lamba);
        // A match object 
        Matcher m = p.matcher(s1);

        // Intercept data 
        boolean ans = m.matches();
        boolean ans2=m.find();
        String ans2A=m.group();
        System.out.println(ans);
        System.out.println(ans2);
        System.out.println(ans2A);
    }

    public void testMatch2()
    {
    
        String s1 = "sss15831asdasdasd&&7762461";
        String lamba = "lasd";
        boolean ans=Pattern.matches(lamba,s1);
        System.out.println(ans);
    }


    public void testMatch3()
    {
    
        String s="asdf^asdcfe^abcde^123";
        String lamba="\\w+";
        Pattern p=Pattern.compile(lamba);
        Matcher m=p.matcher(s);
        while (m.find())
        {
    
            System.out.println(m.group());
        }
    }

    /** @author ToknNan @version 1.0.0 group Search function  */
    public void testMatch4()
    {
    
        String s="[email protected]";
        String lamba="(\\d+)@(\\w{2,3})";
        Pattern p=Pattern.compile(lamba);
        Matcher m=p.matcher(s);
        System.out.println(m.find());
        System.out.println(m.group(1));
        System.out.println(m.group(2));
    }

    /** *  Replacement function  **/
    public void testMatch5()
    {
    

        String s="[email protected]";
        String lamba="[0-9]";
        Pattern p=Pattern.compile(lamba);
        Matcher m=p.matcher(s);
        String ss=m.replaceAll("&");
        System.out.println(ss);
    }

    /** *  Regular expression cuts  * */
    public void testMatch6()
    {
    
        String s="syn1sfasf2gfhg3fgsdg4waf5dasfg6";
       String[] arrs=s.split("\\d+");
       for (String a:arrs)
       {
    
           System.out.println(a);
       }
    }

}

Common expression

chinese

Chinese characters ：[\u4e00-\u9fa5]

Chinese punctuation ：[\u3002\uff1b\uff0c\uff1a\u201c\u201d\uff08\uff09\u3001\uff1f\u300a\u300b]

Chinese comma ：[\uff0c]