How to get the first letter of each word using regular expressions in Java?

The meta-character " \ b " matches word boundaries, [a-zA-Z] matches a character in English letters (two cases). In short, the expression\ \ b [a-zA-Z]　Match a single character in English letters, these two cases are both after each word boundary.

Therefore, to retrieve the first letter of each word-

• Compilecompile()The above expression of the Pattern class method.

• Bypass the required input string asmatcher()The parameters of the Pattern class obtain the Matcher object.

• Finally, for each match, by callinggroup()method to get the matched characters.

Example

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class FirstLetterExample {
　　　public static void main(String[] args) {
　　　　　　Scanner sc = new Scanner(System.in);
　　　　　　System.out.println("Enter sample text: ");
　　　　　　String data = sc.nextLine();
　　　　　　String regex = "\\b[a-zA-Z]";
　　　　　　//Create a pattern object
　　　　　　Pattern pattern = Pattern.compile(regex);
　　　　　　//Create a Matcher object
　　　　　　Matcher matcher = pattern.matcher(data);
　　　　　　System.out.println("First letter of each word from the given string: ");
　　　　　　while(matcher.find()) {
　　　　　　　　　System.out.print(matcher.group())+" ");
　　　　　　}
　　　}
}

Output Result

Enter sample text:
National Intelligence Agency Research & Analysis Wing
First letter of each word from the given string:
N I A R A W