Metoda isDigit(int codePoint) třídy Character obecně určuje, zda daný znak je číslice nebo ne. Obecně je znak považován za číslici, pokud je jeho obecná kategorie daná funkcí getType(codePoint) DECIMAL_DIGIT_NUMBER.
Syntax
public static boolean isDigit(int codePoint)
Parametr
Výše uvedená metoda vyžaduje pouze jeden parametr:
aktuální datum v jazyce Java
a.)CodePoint, což je znak Unicode, který je třeba otestovat.
Návratová hodnota
Metoda isDigit(int codePoint) vrací booleovskou hodnotu, tj. true, pokud je daný (nebo zadaný) znak číslice. Jinak metoda vrací false.
Příklad 1
public class JavaCharacaterisDigitintcodePointExample1 { public static void main(String[] args) { // Initialize the codePoints. int codepoint1 = 55; int codepoint2 = 32; int codepoint3 = 121; int codepoint4 = 49; int codepoint5 = 200; // Check whether a particular codePoint is a digit or not. boolean check1 = Character.isDigit(codepoint1); boolean check2 = Character.isDigit(codepoint2); boolean check3 = Character.isDigit(codepoint3); boolean check4 = Character.isDigit(codepoint4); boolean check5 = Character.isDigit(codepoint5); // Print the result. if(check1){ System.out.print('The codePoint ''+codepoint1+'' is a digit. '); } else{ System.out.print('The codePoint ''+codepoint1+'' is not a digit. '); } if(check2){ System.out.print('The codePoint ''+codepoint2+'' is a digit. '); } else{ System.out.print('The codePoint ''+codepoint2+'' is not a digit. '); } if(check3){ System.out.print('The codePoint ''+codepoint3+'' is a digit. '); } else{ System.out.print('The codePoint ''+codepoint3+'' is not a digit. '); } if(check4){ System.out.print('The codePoint ''+codepoint4+'' is a digit. '); } else{ System.out.print('The codePoint ''+codepoint4+'' is not a digit. '); } if(check5){ System.out.print('The codePoint ''+codepoint5+'' is a digit. '); } else{ System.out.print('The codePoint ''+codepoint5+'' is not a digit. '); } } }Otestujte to hned
Výstup:
The codePoint '55' is a digit. The codePoint '32' is not a digit. The codePoint '121' is not a digit. The codePoint '49' is a digit. The codePoint '200' is not a digit.
Příklad 2
public class JavaCharacaterisDigitintcodePointExample2 { public static void main(String[] args) { // Create four int primitives obj1, obj2, obj3 and obj4. int obj1, obj2, obj3, obj4; // Assign the values to obj1, obj2, obj3 and obj4. obj1 = 0x06f8; obj2 = 0x0432; obj3 = 0x50; obj4 = 0x0c12; // Create four boolean primitives b1, b2, b3 and b4. boolean b1, b2, b3, b4; // Assign the isDigit method b1 = Character.isDigit(obj1); b2 = Character.isDigit(obj2); b3 = Character.isDigit(obj3); b4 = Character.isDigit(obj4); String str1 = 'The first object represents a digit : ' + b1; String str2 = 'The first object represents a digit : ' + b2; String str3 = 'The first object represents a digit : ' + b3; String str4 = 'The first object represents a digit : ' + b4; // Print the values of b1, b2, b3 and b4. System.out.println( str1 ); System.out.println( str2 ); System.out.println( str3 ); System.out.println( str4 ); } }Otestujte to hned
Výstup:
The first object represents a digit : true The first object represents a digit : false The first object represents a digit : false The first object represents a digit : false
Metoda isDigit(char ch) třídy Character obecně určuje, zda daný znak je číslice nebo ne.
Obecně je znak považován za číslici, pokud je jeho obecná kategorie daná pomocí Character.getType(ch) DECIMAL_DIGIT_NUMBER.
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Poznámka: Výše uvedenou metodu nelze použít ke zpracování doplňkových znaků. Abychom podpořili všechny znaky Unicode, včetně všech doplňkových znaků, můžeme použít metodu isdigit(int).
Syntax
public static boolean isDefined(char ch)
Parametr
Výše uvedená metoda vyžaduje pouze jeden parametr
a.)Postava, kterou je třeba otestovat.Návratová hodnota
Metoda isDigit(char ch) vrací booleovskou hodnotu, tj. true, pokud je daný (nebo zadaný) znak číslice. Jinak metoda vrací false.
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Příklad 3
public class JavaCharacterisDigitExample3 { public static void main(String[] args) { // Create three char primitives: obj1, obj2, and obj3. char obj1, obj2, obj3; // Assign the values to obj1, obj2 and obj3 respectively. obj1 = ' '; obj2 = '4'; obj3 = '8'; // Create three boolean primitives b1, b2 and b3. boolean b1, b2,b3; //Assign isDigit results of obj1, obj2 and obj3 to b1, b2, and b3 respectively. b1 = Character.isDigit(obj1); b2 = Character.isDigit(obj2); b3 = Character.isDigit(obj3); String str1 = 'The digit '' + obj1 +'' is:'+b1; String str2 = 'The digit '' + obj2 +'' is:'+b2; String str3 = 'The digit '' + obj3 +'' is:'+b3; // Print the values of b1, b2 and b3. System.out.println( str1 ); System.out.println( str2 ); System.out.println( str3 ); } }Otestujte to hned
Výstup:
The digit ' ' is:false The digit '4' is:true The digit '8' is:true
Příklad 4
import java.util.Scanner; public class JavaCharacterisDigitExample4 { public static void main(String[] args) { // Ask the user to enter the first character. System.out.print('Enter the first character:'); // Use scanner to get the user input. Scanner s1 = new Scanner(System.in); char value1 = s1.nextLine().toCharArray()[0]; // Check whether the input is digit or not. boolean check1 = Character.isDigit(value1); // Print the result if(check1){ System.out.print('The character ''+value1+'' is a digit. '); } else{ System.out.print('The character ''+value1+'' is not a digit. '); } // Ask the user to enter the second character. System.out.print('Enter the first character:'); // Use scanner to get the user input. Scanner s2 = new Scanner(System.in); char value2 = s2.nextLine().toCharArray()[0]; // Check whether the input is digit or not. boolean check2 = Character.isDigit(value2); // Print the result. if(check2){ System.out.print('The character ''+value2+'' is a digit. '); } else{ System.out.print('The character ''+value2+'' is not a digit. '); } } }Otestujte to hned
Výstup:
Enter the first character: & The character '&' is not a digit. Enter the first character: 3 The character '3' is a digit.
Příklad 5
public class JavaCharacterisDigitExample5 { public static void main(String[] args) { // Create four char primitives: obj1, obj2, obj3 and obj4. char obj1, obj2, obj3, obj4; // Assign the values to obj1, obj2, obj3 and obj4 respectively. obj1 = 'A'; obj2 = '3'; obj3 = 'b'; obj4 = '6'; // Create four boolean primitives b1, b2, b3, and b4. boolean b1, b2,b3,b4; // Assign isDigit results of obj1, obj2, obj3, and obj4 to b1, b2 and b3 respectively. b1 = Character.isDigit(obj1); b2 = Character.isDigit(obj2); b3 = Character.isDigit(obj3); b4 = Character.isDigit(obj4); String str1 = 'The digit '' + obj1 +'' is:'+b1; String str2 = 'The digit '' + obj2 +'' is:'+b2; String str3 = 'The digit '' + obj3 +'' is:'+b3; String str4 = 'The digit '' + obj4 +'' is:'+b4; // Print the values of b1, b2, b3 and b4. System.out.println( str1 ); System.out.println( str2 ); System.out.println( str3 ); System.out.println( str4 ); } }Otestujte to hned
Výstup:
The digit 'A' is:false The digit '3' is:true The digit 'b' is:false The digit '6' is:true