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Java program to count the occurrence of pattern matching in the string using regular expression

Given a string, we have to count the occurrence of pattern matching using regular expression.
Submitted by Nidhi, on June 12, 2022

Problem statement

In this program, we will create a string and a regular expression pattern. Then we will count the occurrence of pattern matching in the string using the find() method.

Java program to count the occurrence of pattern matching in the string using regular expression

The source code to count the occurrence of pattern matching in the string using regular expression is given below. The given program is compiled and executed successfully.

// Java program to count the occurrence of pattern matching 
// in the string using regular expression

import java.util.regex.*;

public class Main {
  public static void main(String[] args) {
    String str = "bcd abc xyz abc pqr lmn";
    String regex = "abc";

    int count = 0;

    Pattern pattern = Pattern.compile(regex);
    Matcher matcher = pattern.matcher(str);

    while (matcher.find()) {
      count++;
    }

    System.out.println("Pattern matching count: " + count);
  }
}

Output

Pattern matching count: 2

Explanation

In the above program, we imported the "java.util.regex.*" package to use the Pattern and Matcher classes. Here, we created a public class Main.

The Main class contains a main() method. The main() method is the entry point for the program. And, created a string and pattern. Then we used the find() method to count the occurrence of pattern matching in the string using regular expression and printed the result.

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