Thread: Try-Catch For Specific Numbers?

Hey guys, right now I need the user to either input a 1 or a 2

I am using the following Try-Catch

while (true)
            try {
                num1 = Integer.parseInt(kb.nextLine());
                break;
            } catch (NumberFormatException nfe) {
System.out.print("That is not a number: ");
}

This will limit the possibility to a number, however users can still input any number such as 3, 4, 5, etc.

I have If statements for 1 and 2 and an else for 3

However, how can I re-request an input if any other value is entered. Im slightly confused


Here is the entire code for reference:

package salesperson_part1;
 
//Imports
import java.io.IOException; 
import java.io.InputStreamReader;  
import java.io.BufferedReader; 
import java.util.Scanner;
 
 
public class DriverCalculator {
 
 
    public static void main(String args[]){
 
        //Initializations
        double annualSales;
        SalesPerson sales;
 
           Scanner kb = new Scanner(System.in);
 
        int num1;
        System.out.print("Enter 1 for Total Commission and Annual Sales Calculator,\n"
                    + "Enter 2 for Sales Person Compensation Comparison Calculator: ");
        while (true)
            try {
                num1 = Integer.parseInt(kb.nextLine());
                break;
            } catch (NumberFormatException nfe) {
                System.out.print("That is not a number: ");
            }
 
    if (num1 == 1) {
 
                 //Request Total Sales
        Scanner input=new Scanner(System.in);
        System.out.print("\nThis program will calculate Total Compensation based"
                + " upon\nthe percentage met of the $120,000 Annual Sales Target."
                + "\nThis program will also output a table of possible Total"
                + " Compensations\nin increments of $5,000 up to 1.5 times your inputted Annual Sales\n\n"
                + "Please enter your Total Annual Sales: ");
 
 
         //Check for Correct Entry Data
         try { 
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); 
            String line = in.readLine().trim(); 
 
            //Check for Null Entry
               if (line == null || line.length() == 0) { 
                  System.out.println("You did not enter a value"); 
                  return; 
            } 
 
               //Declare Annual Sales and Replace Commas/Dollar Signs
                annualSales = Double.parseDouble(line.replaceAll(",", "").replaceAll("\\$", ""));
 
            //Check for numerical value
        }   catch (NumberFormatException exception) { 
                 System.out.println("Error: Not a valid sales amount."); 
                 return; 
 
            //Check for IOException
        }   catch (IOException exception) { 
                 System.out.println("Error: " + exception.getLocalizedMessage()); 
                 return; 
        } 
 
         //Declare Sales
        sales=new SalesPerson(annualSales);
 
        //Output Total Commission
        System.out.println("\nYour Total Commission for the year is: $" +
                SalesPerson.commission);
 
        //Output Total Compensation
        System.out.println("Your Total Compensation for the year is: $"+
                String.format("%.2f", sales.getTotalAnnualCompensation())+ "+\n");
 
 
        //Output Table Headers
        System.out.println("Total Sales     |      Total Compensation");
 
        //Set UpperLimit at 150%
        int upperlimit = (int) ((annualSales/2)/5000);
 
        //Calculate Total Compensation in relevance with Total Sales
         for(int i=0;i<=upperlimit;i++){
          sales=new SalesPerson(annualSales);
          System.out.println(" $"+ annualSales+"       |         "
                  +"$"+String.format("%.2f", sales.getTotalAnnualCompensation()));
          annualSales+=5000;   
         }  
    }
     if (num1 == 2) {
             System.out.print("\nSales Person Comparison Program\n");
         }
 
 
    else {
    System.out.print("\nYou did not enter 1 or 2\n");
}
}
}

Originally Posted by Norm

One way would be to use a while loop that keeps looping until a valid value is entered.

I tried that and it worked for checking for 1 and 2, but then after the while loop was initiated if a string was entered the program would fail again. Is there a way to incorporate the try-catch into the whole loop to check for 1 and 2 as well as check for strong values

If so please help me write this

Thank you,

- Deployment

Originally Posted by John Joe

You can use do-while loop and add boolean inside catch block

 public static void main(String[] args) {
        Scanner num = new Scanner(System.in);
        boolean ans = true;
        do {
            try {
                int num1 = Integer.parseInt(num.nextLine());
                while (num1 != 1 && num1 != 2) {
                    System.out.print("You did not enter 1 or 2: ");
                    num1 = Integer.parseInt(num.nextLine());
                }
                break;
            } catch (NumberFormatException ex) {
                System.out.println("Only number is allowed");
                ans = false;
            }
        } while (ans == false);
    }

Thank you, this worked perfectly after moving the "int num1 = Integer.parseInt(num.nextLine());" outside of the loop and fixing a few brackets. Also changed "boolean ans = true;" to "boolean ans;"

This forum is great, and I appreciate the help more than you can imagine

- Deployment