The nextDouble() je metoda klase Java Scanner koja se koristi za skeniranje sljedećeg tokena ulaza kao dvostrukog. Ako je prijevod uspješan, skener prelazi unos koji odgovara.

Sintaksa

Slijedi izjava od nextDouble() metoda:

 public double nextDouble() 

Parametar

Ova metoda ne prihvaća nijedan parametar.

struktura podataka

Povratak

The nextDouble() metoda vraća dvostruko skenirano iz ulaza.

Iznimke

InputMismatchException - Izbacit će ovu iznimku ako sljedeći token ne odgovara regularnom izrazu Float ili je izvan raspona.

NoSuchElementException - Izbacit će ovu iznimku ako je unos iscrpljen.

IllegalStateException - Izbacit će ovu iznimku ako se pozivanje izvrši nakon zatvaranja Scannera.

Verzija kompatibilnosti

Java 1.5 i novije

host linux

Primjer 1

 import java.util.*; public class ScannerNextDoubleExample1 { public static void main(String args[]){ int amount; double balance; //Insert amount and balance from console Scanner input = new Scanner (System.in); System.out.println('Enter the amount: '); amount = input.nextInt(); System.out.println('Enter the Total Balance: '); balance = input.nextDouble(); //reduce amount+fee from balance balance=balance-(amount + 0.50); //print new balance System.out.print('Left Balance is: '+balance); input.close(); } } 

Izlaz:

 Enter the amount: 213734 Enter the Total Balance: 5684566.856 Left Balance is: 5470832.356 

Primjer 2

 import java.util.*; public class ScannerNextDoubleExample2 { public static void main(String args[]){ String str = 'Hello World! 12 + 13.0 = 15 '; Float f = 2.123f; str = str + f; //Create a new scanner with string Object Scanner scanner = new Scanner(str); //Use US locale to be able to identify doubles in the string scanner.useLocale(Locale.US); //Find the next double token and print it while (scanner.hasNext()) { //Check if the next is a double, print found if (scanner.hasNextDouble()) { System.out.println('Found Double:' + scanner.nextDouble()); } //If double is not found, print 'Not Found' System.out.println('Not Found Double:' + scanner.next()); } scanner.close(); } } 

Izlaz:

 Not Found Double:Hello Not Found Double:World! Found Double:12.0 Not Found Double:+ Found Double:13.0 Not Found Double:= Found Double:15.0 Not Found Double:2.123 

Primjer 3

 import java.util.*; public class ScannerNextDoubleExample3 { public static void main(String args[]){ Scanner scan = new Scanner(System.in); System.out.print('Enter value: '); if(scan.hasNextDouble()) { double y = scan.nextDouble(); System.out.println('Your entered Double value: ' +y); } else if (scan.hasNext()) { System.out.println('Please Entered the Double Value.'); System.out.println('You entered: ' + scan.next()); } scan.close() } } 

Izlaz:

 Enter value: 375437.565 Your entered Double value: 375437.565 

Primjer 4

 import java.util.*; public class ScannerNextDoubleExample4 { public static void main(String args[]){ double value; Scanner scan = new Scanner(System.in); System.out.print('Enter the numeric value : '); value = scan.nextDouble(); System.out.println('Double value : ' + value +' 
Twice value : ' + 2.0*value ); scan.close(); } } 

Izlaz:

 Enter the numeric value : 12345 Double value : 12345.0 Twice value : 24690.0