CODEWITHSUNDEEP
javaconditional-statements
TheHadimo
TheHadimo

Reputation: 147

Java how to repeat a statement if it doesn't match a condition

I am trying to get this program to restart if the user input doesn't match the correct format. However I am unsure of how to do this. I have attached the code below:

package weeek4;

import javax.swing.JOptionPane;


public class rollNumber {
public static void main(String[] args) { 

String input = JOptionPane.showInputDialog(null,"Enter your Roll Number in        this format **-***-*****");

if (input.matches("\\d{2}-\\d{3}-\\d{5}")) {
JOptionPane.showMessageDialog(null,"Thank you");
}
else {
    JOptionPane.showMessageDialog(null,"Invalid Number");
    }


}
}

Upvotes: 0

Views: 767

Answers (1)

m0bi5
m0bi5

Reputation: 9472

It is quite easy . Just use a loop(A statement that repeats a block of code until a certain condition is met) and a flag variable(in this case , k checks for the condition in the while loop)

package weeek4;

import javax.swing.JOptionPane;


public class rollNumber 
{
   public static void main(String[] args) 
   { 

      String input = JOptionPane.showInputDialog(null,"Enter your Roll Number in        this format **-***-*****");
      int k = 0;
      while (k!=1)
      {
         if (input.matches("\\d{2}-\\d{3}-\\d{5}")) {
            JOptionPane.showMessageDialog(null,"Thank you");
            k=1;
         }
         else
            JOptionPane.showMessageDialog(null,"Invalid Number");
      }


    }
}

Hope I helped :)

Upvotes: 1

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