CODEWITHSUNDEEP
javaloopsinput
AB3
AB3

Reputation: 67

How to stop scanning after I input a certain line?

I want to build a program that only stops scanning for strings until after I input "0" in the console, how do I do that?

I assume I can use do while loop, but I don't know what to put in the while() condition.

    Scanner scan = new Scanner(System.in);

    do {

        String line = scan.nextLine(); 

        //do stuff

    } while(); //what do i put in here to stop scanning after i input "0"

Thanks in advance, I'm new to Java and OOP in general.

Upvotes: 0

Views: 1093

Answers (2)

Abhinav Chauhan
Abhinav Chauhan

Reputation: 1384

You don't have to use any loop , as you said you want to stop input when 0 is pressed by default for nextLine() the input stops when user press the enter key because it is the delimiter , so just change the delimiter 

Scanner scanner = new Scanner(System.in);
scanner.useDelimiter("0");   //regex
String s = scanner.next(); // no matter what user enters the s will contain the input before 0

Upvotes: 1

Jason
Jason

Reputation: 5246

You can use a while loop instead of a do-while loop. Define a String that will be initialized inside the while loop. On each iteration we assign the String to Scanner#nextLine and check if that line is not equal to 0. If it is, the while-loop prevents iteration.

        Scanner scan = new Scanner(System.in);

        String line;

        while (!(line = scan.nextLine()).equals("0")) {
            System.out.println("line: " + line);
        }

Upvotes: 1

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