पैटर्न कम्पाइल करना

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

public class Main {
    public static void main(String[] args) {
        Pattern p = Pattern.compile("\\d+");
        Matcher m = p.matcher("abc123");
        System.out.println(m.find());
    }
}

import java.util.regex.Pattern;

public class Main {
    static final Pattern DIGITS = Pattern.compile("\\d+");

    public static void main(String[] args) {
        System.out.println(DIGITS.matcher("a1").find());
        System.out.println(DIGITS.matcher("bb").find());
    }
}

import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        Pattern word = Pattern.compile("\\w+");
        System.out.println(word.matcher("hello").matches());
    }
}

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

public class Main {
    public static void main(String[] args) {
        Pattern p = Pattern.compile("cat");
        Matcher m = p.matcher("the cat sat");
        System.out.println(m.find());
    }
}

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

public class Main {
    public static void main(String[] args) {
        Pattern p = Pattern.compile("\\d");
        Matcher m = p.matcher("a1b2");
        System.out.println(m.find());
        System.out.println(m.find());
    }
}

import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        Pattern p = Pattern.compile("java", Pattern.CASE_INSENSITIVE);
        System.out.println(p.matcher("I love JAVA").find());
    }
}

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

public class Main {
    public static void main(String[] args) {
        Pattern p = Pattern.compile("^a", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE);
        Matcher m = p.matcher("apple\nApricot");
        int count = 0;
        while (m.find()) count++;
        System.out.println(count);
    }
}

import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        System.out.println(Pattern.matches("\\d{3}", "123"));
        System.out.println(Pattern.matches("\\d{3}", "12"));
    }
}

import java.util.Arrays;
import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        Pattern comma = Pattern.compile("\\s*,\\s*");
        String[] parts = comma.split("a, b ,c,  d");
        System.out.println(Arrays.toString(parts));
    }
}

import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        Pattern p = Pattern.compile("[a-z]+", Pattern.CASE_INSENSITIVE);
        System.out.println(p.pattern());
        System.out.println(p.flags());
    }
}

import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

public class Main {
    public static void main(String[] args) {
        try {
            Pattern.compile("[unclosed");
        } catch (PatternSyntaxException e) {
            System.out.println("Invalid regex");
        }
    }
}