Asking for user input until value between -5 and 5 is entered in java-CodePudding

I'm trying to creating some code which asks for user input until the value being entered is between -5 and 5 but am having some trouble with it, currently it works the first time an invalid input is entered but if a second invalid input is entered then the program accepts that value, my current code is:

            int choice;
            Scanner sc = new Scanner(System.in);
            choice = sc.nextInt();
            if(choice<=-5 || choice>=5)
            {
                    System.out.println("==================================" "\n" "INVALID INPUT! PLEASE TRY AGAIN: " "\n" "==================================");                               
                    choice = sc.nextInt();
            }
            else
            {
                    // do stuff
            }

CodePudding user response：

The code you've posted has no notion of doing something "until" some condition is met - you're only reading the input once and then making a decision based on that. You need to go and learn about loops for repeating things.

CodePudding user response：

First, you need to start with an infinite loop like while that runs until a number between -5 and 5 is entered then you do break

And since you want to read the user's input then you need to specify a condition for the while loop like while(input.hasNext()).

Also, reading inputs with hasNext() returns a String so you need to change it to int with parseInt(n)

import static java.lang.Integer.parseInt;
import java.util.Scanner;

public class Mavenproject1 {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        while (input.hasNext()) {
            String n = input.next();
            int number = parseInt(n);
            if (number >= -5 && number <= 5) {
                System.out.println("==================================" "\n" "INVALID INPUT! PLEASE TRY AGAIN: " "\n" "==================================");   
                break;
            }
//            System.out.println(n);
            
        }
        input.close();
    }
}

You can as well use hasNextInt() & nextInt() if you are sure inputs are always integers value so you don’t need to parse the string into int:

import java.util.Scanner;

public class Mavenproject1 {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        while (input.hasNextInt()) {
            int n = input.nextInt();
            if (n >= -5 && n <= 5) {
                System.out.println("==================================" "\n" "INVALID INPUT! PLEASE TRY AGAIN: " "\n" "==================================");   
                break;
            }
//            System.out.println(n);
            
        }
        input.close();
    }
}