Advanced Programming-Week8

Programming 课程第八周的课堂练习

本周主要练习使用正则表达式进行匹配。

Summary

1. final 关键字
2. Pattern 类
   1. compile() 方法
   2. matcher() 方法
   3. CASE_INSENSITIVE 常量
3. Matcher 类
   1. find() 方法
   2. group() 方法
   3. groupCount() 方法

Practice 1

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

public class practice1 {
    public static void main(String []args)
    {
        final String regex="s";
        final String string="First Semester Students";

        final Pattern pattern=Pattern.compile(regex,Pattern.CASE_INSENSITIVE);
        final Matcher matcher=pattern.matcher(string);

        while(matcher.find())
        {
            System.out.println("Full match:"+matcher.group());

            for(int i=1;i<=matcher.groupCount();i++)
            {
                System.out.println("Group" + i +":"+matcher.group(i));
            }
        }
    }
}

Practice 2

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

public class practice2 {
    public static void main(String []args)
    {
        final String regex="s.";
        final String string="First Semester Students";

        final Pattern pattern=Pattern.compile(regex,Pattern.CASE_INSENSITIVE);
        final Matcher matcher=pattern.matcher(string);

        while(matcher.find())
        {
            System.out.println("Full match:"+matcher.group(0));

            for(int i=1;i<=matcher.groupCount();i++){
                System.out.println("Group"+i+":"+matcher.group(i));
            }
        }
    }
}

Practice 3

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

public class practice3 {
    public static void main(String []args)
    {
        final String regex="a{3,6}";
        final String string="a aa aaa aaaa aaaaaaaaaa";

        final Pattern pattern=Pattern.compile(regex);
        final Matcher matcher=pattern.matcher(string);

        while(matcher.find())
        {
            System.out.println("Full match:"+matcher.group(0));

            for(int i=1;i<matcher.groupCount();i++)
            {
                System.out.print("Group"+i+":"+matcher.group(i));
            }
        }
    }
}

Practice 4

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

public class practice4 {
    public static void main(String []args)
    {
        final String regex="([a-z]{1,10})";
        final String string="abc123DEF this is for lab practice";

        final Pattern pattern=Pattern.compile(regex,Pattern.CASE_INSENSITIVE);
        final Matcher matcher=pattern.matcher(string);

        while(matcher.find())
        {
            System.out.println("Full match:"+matcher.group(0));

            for(int i=0;i<matcher.groupCount();i++)
            {
                System.out.println("Group "+i+" : "+matcher.group(i));
            }
        }
    }
}