CODEWITHSUNDEEP
javainputwhile-loopjava.util.scanner
rishiag
rishiag

Reputation: 2274

Why my program in not exiting out of while loop?

Code: 

int size=0;
Scanner in = new Scanner(System.in);     
System.out.println("Enter size of the Graph");
size = in.nextInt();
System.out.println(size);
for (int i = 1; i <= size; i++) {
    Scanner in2 =new Scanner(System.in);
    while(in2.hasNextInt()){
        int num = in2.nextInt();
        System.out.print("(" + i + "," + num + ")"+",");
        System.out.println();
    }
    System.out.println("out of the while loop");
}

Input & Output:

Enter size of the Graph
4
4
2 3 4
(1,2),
(1,3),
(1,4),
2 5 6
(1,2),
(1,5),
(1,6),

As you can see my program doesn't exists while loop. It still prints the value for i=1. What I am doing wrong?

Upvotes: 0

Views: 146

Answers (2)

Bhesh Gurung
Bhesh Gurung

Reputation: 51030

int num = in2.nextInt();

try adding in2.nextLine(); after that.

Note:

You shouldn't be doing new Scanner(System.in); multiple times.

Scanner in2 = new Scanner(System.in); // this is useless just use in

Upvotes: 1

amit
amit

Reputation: 178431

Your program is constantly waiting for a new feed, in order to terminate it - you should indicate the input was ended (or provide a non int input).

To indicate the feed ended - you should provide EOF - which is ctrl+D in linux and ctrl+Z in windows.

Upvotes: 1

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