The hasNext() je metoda razreda Java Scanner, ki vrne true, če ima ta skener drug žeton v svojem vhodu. obstajajo tri različne vrste Java Scannerja hasNext() metoda, ki jo je mogoče razlikovati glede na njen parameter. To so:

1. Metoda Java Scanner hasNext ().
2. Metoda Java Scanner hasNext (vzorec niza).
3. Java Scanner ima metodo Next(Pattern pattern).

1. Metoda Java Scanner hasNext ():

Je metoda razreda Scanner, ki vrne true, če ima ta skener drug žeton v svojem vhodu. Ta metoda se lahko blokira med čakanjem na vnos za skeniranje.

2.Java Scanner hasNext (vzorec niza) Metoda:

Je metoda razreda Scanner, ki vrne true, če se naslednji žeton ujema z vzorcem, sestavljenim iz podanega niza.

3. Metoda Java Scanner hasNext (vzorec vzorca):

Je metoda razreda Scanner, ki vrne true, če se naslednji popolni žeton ujema s podanim vzorcem.

Sintaksa

Sledijo izjave hasNext() metoda:

if in else v bash

 public boolean hasNext() public boolean hasNext(String pattern) public boolean hasNext(Pattern pattern) 

Parameter

Vračila

Izjeme

IllegalStateException - Ta metoda vrže izjemo, če se priklic izvede po zaprtju optičnega bralnika.

Združljivostna različica

Java 1.5 in novejši

Primer 1

 import java.util.*; public class ScannerHasNextExample1 { public static void main(String args[]){ //Create Scanner object Scanner scan = new Scanner('Hello World!'); //Printing the delimiter used System.out.println('Delimiter:' + scan.delimiter()); //Print the Strings while (scan.hasNext()) { System.out.println(scan.next()); } //Close the scanner scan.close(); } } 

Izhod:

 Delimiter:p{javaWhitespace}+ Hello World! 

Primer 2

 import java.util.*; public class ScannerHasNextExample2 { public static void main(String args[]){ String s = 'Hello, This is JavaTpoint.'; //Create scanner Object and pass string in it Scanner scan = new Scanner(s); //Check if the scanner has a token System.out.println('Result: ' + scan.hasNext()); //Print the string System.out.println('String: ' +scan.nextLine()); //Check if the scanner has a token after printing the line System.out.println('Final Result: ' + scan.hasNext()); //Close the scanner scan.close(); } } 

Izhod:

 Result: true String: Hello, This is JavaTpoint. Final Result: false 

Primer 3

 import java.util.*; public class ScannerHasNextExample3 { public static void main(String args[]){ //Create Scanner object Scanner scan = new Scanner('Program:Java;Python;Android'); //Initialize the String pattern String pattern = 'Program:.*'; //Check if pattern satisfies the String content if(scan.hasNext(pattern)){ System.out.println('Pattern found'); } else{ System.out.println('Pattern not found'); } scan.close(); } } 

Izhod:

primerjava nizov v Javi

 Pattern found 

Primer 4

 import java.util.*; public class ScannerHasNextExample4 { public static void main(String args[]){ String str = 'JavaTpoint.com 15 + 15 = 18.0'; Scanner scanner = new Scanner(str); //Checking scanner's next token matches 'c' System.out.println('Result: '+scanner.hasNext('JavaTpoint.com')); //Checking scanner's next token matches '=' System.out.println('Result: '+scanner.hasNext('=')); //Print the rest of the string System.out.println('Rest of String: '+scanner.nextLine()); scanner.close(); } } 

Izhod:

 Result: true Result: false Rest of String: JavaTpoint.com 15 + 15 = 18.0 

Primer 5

 import java.util.*; import java.util.regex.Pattern; public class ScannerHasNextExample5 { public static void main(String args[]){ //Create Scanner object Scanner scan = new Scanner('Names:Raju1;Pawan;Suresh'); //Declare the delimiter scan.useDelimiter(';'); /*Initialize the String pattern which signifies that the String token contains characters of the alphabet only*/ Pattern pattern = Pattern.compile('[A-Za-z]*'); while(scan.hasNext()){ //Check if the token consists of declared pattern if(scan.hasNext(pattern)){ System.out.println(scan.next()); } else scan.next(); } scan.close(); } } 

Izhod:

 Pawan Suresh