Java Character isDigit() example

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

1. Character isDigit() Method Overview

Definition:

The isDigit() method of the Java Character class determines if a given character (specified as a char or an int code point) is a digit. A character is considered a digit if it's a decimal digit, which means it belongs to the range '0' through '9'.

Syntax:

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

Parameters:

char ch: The character to be tested.

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

Key Points:

- It is used to ascertain if a character is one of the ten decimal digits.

- The method returns true if the character is a digit, and false otherwise.

- Unicode provides representations for various character sets across languages; therefore, this method can also identify digits in scripts other than Latin (like Arabic numerals).

2. Character isDigit() Method Example

public class IsDigitExample {
    public static void main(String[] args) {
        char testChar1 = '5';
        char testChar2 = 'A';
        int testCodePoint = 0x0662;  // Arabic numeral '2'

        System.out.println("Is '" + testChar1 + "' a digit? " + Character.isDigit(testChar1));
        System.out.println("Is '" + testChar2 + "' a digit? " + Character.isDigit(testChar2));
        System.out.println("Is Arabic numeral represented by code point " + testCodePoint + " a digit? " + Character.isDigit(testCodePoint));
    }
}

Output:

Is '5' a digit? true
Is 'A' a digit? false
Is Arabic numeral represented by code point 1634 a digit? true

Explanation:

The example demonstrates the isDigit() method by testing two Latin characters and one Arabic numeral. The method identifies the characters '5' and the Arabic numeral represented by the Unicode code point 0x0662 (which is '2' in Arabic) as digits and returns true. However, it returns false for the character 'A' since it's not a digit.