Could you help me to understand why I need to type 2 times to allow scanner to scan my input data. What I am basically check in below piece of code is to validate if number is a int type and is above 0 to ask number of players playing the game (guessing number game)
Validation code works perfectly fine but...I need to type digit 2 times...
package pakiet;
import java.util.Random;
import java.util.Scanner;
public class GraModyfikacjaLiczbyGraczy {
public static void main(String[] args) {
Random rand = new Random();
int los = rand.nextInt(11);
int liczbaGraczy; // number of players
Scanner scan7 = new Scanner(System.in); // zamknac
System.out.println("Type number of players");
while (!scan7.hasNextInt() || scan7.nextInt() < 0) {
System.out.println("Type number of players");
scan7 = new Scanner(System.in);
}
liczbaGraczy = scan7.nextInt();
You initialize Scanner
2 times thats why -
In while loop -
while (!scan7.hasNextInt() || scan7.nextInt() < 0) {
System.out.println("Type number of players");
//Issue here
scan7 = new Scanner(System.in);
}
You can simply use scan7.next()
for next input.
You can use do-While
loop properly to achieve this -
public static void main(String[] args) {
Random rand = new Random();
int los = rand.nextInt(11);
int liczbaGraczy; // number of players
Scanner scan7 = new Scanner(System.in); // zamknac
System.out.println("Type number of players");
do {
while (!scan7.hasNextInt()){
System.out.println(" Type number of players :");
scan7.next();
}
liczbaGraczy = scan7.nextInt();
}while (liczbaGraczy < 0);
System.out.println("Number of players :"+liczbaGraczy);
}
Hope this will help.
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