The nextDouble() yra „Java Scanner“ klasės metodas, naudojamas kitam įvesties žetonui nuskaityti kaip dvigubai. Jei vertimas sėkmingas, skaitytuvas aplenks atitikusią įvestį.

Sintaksė

Toliau pateikiama deklaracija nextDouble() metodas:

 public double nextDouble() 

Parametras

Šis metodas nepriima jokių parametrų.

Grąžina

The nextDouble() metodas grąžina dvigubai nuskaitytą iš įvesties.

Išimtys

InputMimatchException - Ji išmes šią išimtį, jei kitas prieigos raktas neatitiks Float reguliariosios išraiškos arba yra už diapazono ribų.

NoSuchElementException - Išskirs šią išimtį, jei įvestis bus išnaudota.

IllegalStateException - Ši išimtis bus pateikta, jei iškvietimas bus atliktas uždarius skaitytuvą.

Suderinamumo versija

Java 1.5 ir naujesnės versijos

1 pavyzdys

 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(); } } 

Išvestis:

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

2 pavyzdys

 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(); } } 

Išvestis:

 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 

3 pavyzdys

 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() } } 

Išvestis:

 Enter value: 375437.565 Your entered Double value: 375437.565 

4 pavyzdys

 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(); } } 

Išvestis:

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