Character isDigit() method in Java with examples Improve Improve Like Article Like Save Share Report The java.lang.Character.isDigit(char ch) is an inbuilt method in java which determines whether a specified character is a digit or not. There are few conditions that a character must accomplish to be accepted as a digit. That is if the general category type of a character, provided by Character.getType(ch), is DECIMAL_DIGIT_NUMBER, then the character is a digit. Some Unicode character ranges that contain digits: From ‘\u0030’ to ‘\u0039’ : ISO-LATIN-1 digits (‘0’ through ‘9’) From ‘\u0660’ to ‘\u0669’ : Arabic-Indic digits From ‘\u06F0’ to ‘\u06F9’ : Extended Arabic-Indic digits From ‘\u0966’ to ‘\u096F’ : Devanagari digits From ‘\uFF10’ to ‘\uFF19’ : Fullwidth digits Apart from the above mentioned ranges, many other character ranges contain digits as well. Syntax: public static boolean isDigit(char ch) Parameter: This method accepts character parameter ch as an argument, which is to be tested. Return value:This method returns a boolean value. It returns True if ch is digit, else False. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isDigit(int) method. Below programs illustrate the above method: Program 1: // Java program to illustrate the // Character.isDigit() method import java.util.*; import java.lang.*; public class GFG { public static void main(String[] args) { // two characters char c1 = 'A', c2 = '4'; // Function to check if the character // is digit or not System.out.println( c1 + " is a digit -> " + Character.isDigit(c1)); System.out.println( c2 + " is a digit -> " + Character.isDigit(c2)); } } Output: A is a digit -> false 4 is a digit -> true Program 2: // Java program to illustrate the // Character.isDigit() method import java.util.*; import java.lang.*; public class GFG { public static int search_digit(String s) { // Function to check if is digit // is found or not for (int i = 0; i < s.length(); i++) { if (Character.isDigit( s.charAt(i)) == true) { // return position of digit return i + 1; } } // return 0 if digit not present return 0; } public static void main(String[] args) { // Array of strings String[] arr = { "ABC4DEF", "QWERTY" }; // To store the position of digit int index = 0; // Traverse the array arr[] to find digit // within it's elements for (String x : arr) { index = search_digit(x); if (index != 0) { System.out.println( "Digit found at : " + (index) + "th position."); } else { System.out.println( "Digit not present."); } } } } Output: Digit found at : 4th position. Digit not present. The java.lang.Character.isDigit(int codePoint) is an inbuilt method in java which determines whether the specified Unicode code point character of integer type is a digit or not. There are few conditions that a character must accomplish to be accepted as a digit. That is if the general category type of a character, provided by getType(codepoint), is a DECIMAL_DIGIT_NUMBER, then the character is a digit. Some Unicode character ranges that contain digits: From ‘\u0030’ to ‘\u0039’ : ISO-LATIN-1 digits (‘0’ through ‘9’) From ‘\u0660’ to ‘\u0669’ : Arabic-Indic digits From ‘\u06F0’ to ‘\u06F9’ : Extended Arabic-Indic digits From ‘\u0966’ to ‘\u096F’ : Devanagari digits From ‘\uFF10’ to ‘\uFF19’ : Fullwidth digits Apart from the above mentioned ranges, many other character ranges contain digits as well. Syntax: public static boolean isDigit(int codePoint) Parameter: This method accepts unicode character parameter codePoint of integer type as an argument, which is to be tested. Return value: This method returns a boolean value. It returns True if the specified character is digit, else it returns False. Below programs illustrate the above method: Program 1: // This program demonstrates the use of // isDigit(int codePoint) method of Character class. import java.util.*; public class GFG { public static void main(String[] args) { // create codePoints int cp1 = 57; int cp2 = 84; // Check whether the codePoints // are digit or not. System.out.println( "The codePoint cp1 is a digit -> " + Character.isDigit(cp1)); System.out.println( "The codePoint cp2 is a digit -> " + Character.isDigit(cp2)); } } Output: The codePoint cp1 is a digit -> true The codePoint cp2 is a digit -> false Program 2: // This program demonstrates the use of // isDigit(int codePoint) method of // Character class. import java.util.*; public class Main { public static void main(String[] args) { // create codePoints int cp1 = 0x50; int cp2 = 0x06f8; // Check whether the codePoints // are digit or not. System.out.println( "The codePoint cp1 is a digit -> " + Character.isDigit(cp1)); System.out.println( "The codePoint cp2 is a digit -> " + Character.isDigit(cp2)); } } Output: The codePoint cp1 is a digit -> false The codePoint cp2 is a digit -> true Reference: https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html#isDigit-char- Last Updated : 17 May, 2020 Like Article Save Article Previous CompoundName remove() method in Java with Examples Next Execution Engine in Java Share your thoughts in the comments Add Your Comment Please Login to comment...