Check if a String Contains only Alphabets in Java

Learn how to check if a string contains only alphabet characters in Java using regular expression . here regular expression [A-Za-z]+ checks whether the string contains only uppercase (A-Z) or lowercase (a-z) letters from start to end.

Code Explanation (Step-by-Step) :

  • We take a String variable word containing the input text.
  • Create a method named checkAlphabet() to check whether the String contains only alphabets.
  • Inside the method, first check that the String is not null and not empty.
  • Use the regular expression [A-Za-z]+ with the matches() method to verify that the String contains only uppercase (A-Z) and lowercase (a-z) letters.
  • The method returns a boolean value:
    • true if the String contains only alphabets.
    • false otherwise.
  • Now Print the returned boolean value as the output.
				
					public class TestAlphabet {

    public static void main(String[] args) {
        String str = "Welcome";
        boolean status = checkAlphabet(str);
        System.out.println("String contains only alphabets: " + status);
    }

    public static boolean checkAlphabet(String str) {
        return str != null && !str.isEmpty() && str.matches("[A-Za-z]+");
    }
}

Output :-
String contains only alphabets: true

Java Program to Validate Alphabetic Strings

				
					public class TestAlphabet {

    public static void main(String[] args) {
        String str = "Welcome";

        boolean status = checkAlphabet(str);

        System.out.println("String contains only alphabets: " + status);
    }

    public static boolean checkAlphabet(String str) {

        if (str == null || str.isEmpty()) {
            return false;
        }

        for (char ch : str.toCharArray()) {
            if (!Character.isLetter(ch)) {
                return false;
            }
        }

        return true;
    }
}

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