Java Character isLetter() example

In this guide, you will learn about the Character isLetter() method in Java programming and how to use it with an example.

1. Character isLetter() Method Overview

Definition:

The isLetter() method of the Java Character class determines if the given character (specified as a char or an int code point) is a letter. 

Syntax:

1. static boolean isLetter(char ch) 
2. static boolean isLetter(int codePoint)

Parameters:

char ch: The character to be tested.

int codePoint: The character (Unicode code point) to be tested.

Key Points:

- The method is utilized to determine if a character is considered a letter in terms of Unicode categorization.

- It returns true if the character is a letter, and false otherwise.

- The method is capable of recognizing letters from multiple scripts and languages due to its reliance on the Unicode standard.

2. Character isLetter() Method Example

public class IsLetterExample {
    public static void main(String[] args) {
        char testChar1 = 'A';
        char testChar2 = '5';
        int testCodePoint = 0x3041;  // Hiragana letter 'a'

        System.out.println("Is '" + testChar1 + "' a letter? " + Character.isLetter(testChar1));
        System.out.println("Is '" + testChar2 + "' a letter? " + Character.isLetter(testChar2));
        System.out.println("Is Hiragana letter represented by code point " + testCodePoint + " a letter? " + Character.isLetter(testCodePoint));
    }
}

Output:

Is 'A' a letter? true
Is '5' a letter? false
Is Hiragana letter represented by code point 12353 a letter? true

Explanation:

In the example, the isLetter() method is tested using two Latin characters and a Hiragana letter from Japanese. 

The method correctly identifies the characters 'A' and the Hiragana letter represented by the Unicode code point 0x3041 as letters, thus returning true. However, for the character '5', which is not a letter, it returns false.