Java Regular expression to check if a string contains alphabet

JavaObject Oriented ProgrammingProgramming

Following is the regular expression to match alphabet in the given input −

"^[a-zA-Z]*$"

Where,

  • ^ matches the starting of the sentence.
  • [a-zA-z] matches the lower case and upper case letters.
  • * indicates the occurrence for zero or more times.
  • & indicates the end of the line.

Example 1

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class ContainsAlphabetExample {
   public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      String names[] = new String[5];
      for(int i=0; i<names.length;i++){
         System.out.println("Enter your name: ");
         names[i] = sc.nextLine();
      }
      //Regular expression to accept English alphabet
      String regex = "^[a-zA-Z]*$";
      //Creating a pattern object
      Pattern pattern = Pattern.compile(regex);
      for (String name : names) {
         //Creating a Matcher object
         Matcher matcher = pattern.matcher(name);
         if(matcher.matches()) {
            System.out.println(name+" is a valid name");
         } else {
            System.out.println(name+" is not a valid name");
         }
      }
   }
}

Output

Enter your name:
krishna
Enter your name:
kasyap
Enter your name:
maruthi#
Enter your name:
Sai_Ram
Enter your name:
Vani.Viswanath
krishna is a valid name
kasyap is a valid name
maruthi# is not a valid name
Sai_Ram is not a valid name
Vani.Viswanath is not a valid name

Example 2

import java.util.Scanner;
public class Just {
   public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter your name: ");
      String name = sc.nextLine();
      String regex = "^[a-zA-Z]*$";
      boolean result = name.matches(regex);
      if(result) {
         System.out.println("Given name is valid");
      } else {
         System.out.println("Given name is not valid");
      }
   }
}

Output

Enter your name:
vasu#dev
Given name is not valid
raja
Published on 21-Nov-2019 12:15:35
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