Character.getNumericValue() - Numeric Value of Code Point

Unicode Tutorials - Herong's Tutorial Examples

∟Character.getNumericValue() - Numeric Value of Code Point

This section provides tutorial example on how to test 'Character' class getNumericValue() static methods to obtain the numeric value associated with a given Unicode character.

One interesting static method offered in the "Character" class is the "getNumericValue(int codePoint)" method, which returns a numeric value represented by the given Unicode character.

Here is a tutorial example on how to use "getNumericValue()" and other related methods:

/* UnicodeCharacterNumeric.java
 * Copyright (c) 2019 HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import java.nio.*;
import java.nio.charset.*;
class UnicodeCharacterNumeric {
   static int[] unicodeList = {0x37, 0x0667, 0x2166, 0x3286, 0x4E03, 
      0x1F108};
   public static void main(String[] arg) {
      try {     
         for (int i=0; i<unicodeList.length; i++) {

// Starting with the code point value
            int codePoint  = unicodeList[i];

// Dumping data in HEX numbers
            System.out.print("\n");
            System.out.print("\n                 Code point: "
               +Integer.toHexString(codePoint).toUpperCase());

// Getting Unicode character numeric values
            System.out.print("\n                isDefined(): "
               +Character.isDefined(codePoint));
            System.out.print("\n                  getName(): "
               +Character.getName(codePoint));
            System.out.print("\n          getNumericValue(): "
               +Character.getNumericValue(codePoint));
               
// Getting Unicode character type
            int intType = Character.getType(codePoint);
            System.out.print("\n                  getType(): "
               +intType);
            System.out.print("\n    is DECIMAL_DIGIT_NUMBER: "
               +(intType==Character.DECIMAL_DIGIT_NUMBER));
            System.out.print("\n                  isDigit(): "
               +Character.isDigit(codePoint));
         }
      } catch (Exception e) {
         System.out.print("\n"+e.toString());
      }
   }
}

Compile and run it with Java 11:

C:\herong>javac UnicodeCharacterNumeric.java

C:\herong>java UnicodeCharacterNumeric

                 Code point: 37
                  getName(): DIGIT SEVEN
          getNumericValue(): 7
                  getType(): 9
    is DECIMAL_DIGIT_NUMBER: true
                  isDigit(): true

                 Code point: 667
                  getName(): ARABIC-INDIC DIGIT SEVEN
          getNumericValue(): 7
                  getType(): 9
    is DECIMAL_DIGIT_NUMBER: true
                  isDigit(): true

                 Code point: 2166
                  getName(): ROMAN NUMERAL SEVEN
          getNumericValue(): 7
                  getType(): 10
    is DECIMAL_DIGIT_NUMBER: false
                  isDigit(): false

                 Code point: 3286
                  getName(): CIRCLED IDEOGRAPH SEVEN
          getNumericValue(): 7
                  getType(): 11
    is DECIMAL_DIGIT_NUMBER: false
                  isDigit(): false

                 Code point: 4E03
                  getName(): CJK UNIFIED IDEOGRAPHS 4E03
          getNumericValue(): -1
                  getType(): 5
    is DECIMAL_DIGIT_NUMBER: false
                  isDigit(): false

                 Code point: 1F108
                  getName(): DIGIT SEVEN COMMA
          getNumericValue(): 7
                  getType(): 11
    is DECIMAL_DIGIT_NUMBER: false
                  isDigit(): false

Some interesting notes on the output:

Many Unicode characters that are not defined as digits, but they have numeric values. This is understandable. For example, "DIGIT SEVEN COMMA", 0x1F108, is not a digit. But it has a numeric value of 7. See the glyph of 0x1F108:
It is strange to see that "ARABIC-INDIC DIGIT SEVEN", 0x0667, has numeric value of 7 and is defined as a digit! See the glyph of 0x0667:
For some reason, the Chinese digit seven, 0x4E03, has no numeric value and is not defined as a digit! See the glyph of 0x4E03: