I just recently learned about the try/catch block and how once the expection is thrown the program will exit. In the photo below the code the Expection is caught once the user enters "a" instead of a random number.

Is there any way the user could reenter the value without the Expection being thrown again?

import java.util.Scanner
public class user_Num {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int random_Num = 0;
        try {
            System.out.println("Enter a random number:");
            random_Num = input.nextInt();
            if (random_Num > 0) {
                System.out.println("The user entered a number that is positive.");
            } else if (random_Num<0) {
                System.out.println("The user entered a number that is negative");
            }
        } catch (Exception e) {
            System.out.println("Error: "   e);
        }
        System.out.println("Enter a random number:");
        random_Num = input.nextInt();
        System.out.println("User Input Taken.");
    }
}

Program Result:

CodePudding user response：

Yeah this is pretty easy you just have to revert back to whole code in the catch block. You could also have a thread.

import java.util.Scanner
        public class user_Num{
        public static void main(String[] args) {
         Scanner input = new Scanner(System.in);
         int random_Num = 0;
               
         Thread t1=new Thread(new Runnable() {
                  @Override
                  public void run()
                  {
                    System.out.println("Enter a random number:");
                      random_Num = input.nextInt();
                      if(random_Num > 0){
                          System.out.println("The user entered a number that is 
                          positive.");
                      } else if (random_Num < 0){
                          System.out.println("The user entered a number that is 
                          negative");
                      }

                  }
              });
                  try {

                       t1.start();
                       t1.close();
                                        } catch (Exception e){
                      System.out.println("Error: "  e);
                      System.out.println("Your input is not a number.");
                      t1.start();
                    
                }
            }
          }
        }

CodePudding user response：

You have to add flag variable for findout exception is occured or not.

Here is two senario for exception occured or not:

• If exception is occured then flagvariable is become false and terminate while loop.
• If exception is not occurred then flag variable is become true and you are again going to while loop.

Here dow is code:

import java.util.Scanner;
public class Main{
    public static void takeInput()
    {
        Scanner input = new Scanner(System.in);
        System.out.println("Enter a random number:");
        int random_Num = input.nextInt();
        if(random_Num > 0){
            System.out.println("The user entered a number that is positive.");
        } else if (random_Num < 0){
            System.out.println("The user entered a number that is negative");
        }
    }
    
    public static void main(String[] args) {
        boolean flag = true;
        while(flag)
        {
            try {
                takeInput();
                flag = false;
            } catch (Exception e){
                flag = true;
            }
        }
    }
}

Class name always start from uppercase letter