Write a Java method, reverseDigit, that takes an integer as a parameter and retu

Question

Write a Java method, reverseDigit, that takes an integer as a parameter and returns the number with its digits reversed. For example, (12345) is 54321. Also, write a program to test your method.

I have the answer, I just can't figure out how to add code for a negative and keep it negative, ie: -1234 reversed -4321.

import java.util.Random;
import java.util.Scanner;
public class reverseDigit
{
public static void main(String[] args)
{
//Program Test input to method
Random rand = new Random();
int x=rand.nextInt(10000); //Generates a random number to test
System.out.println("Sample random integer is: "+x);
System.out.println("The reversed integer is: "+reverseDigit(x));
//Program User Input to method
Scanner in=new Scanner(System.in);
System.out.print("Enter an integer: "); //asks for input integer
System.out.println("The reversed integer is: "+reverseDigit(in.nextInt())); //prints reversed integer
}
//reverseDigit method
public static int reverseDigit(int integer)
{
int reverseInteger=0;
while(integer>0)
{
reverseInteger=10*reverseInteger+(integer%10); //reverses the integer
integer/=10;
}
return reverseInteger;
}
}

Explanation / Answer

Note: Modified code has been highlighted

Program Code:

import java.util.Random;
import java.util.Scanner;
public class reverseDigit
{
   public static void main(String[] args)
   {
       //Program Test input to method
       Random rand = new Random();
       int x=rand.nextInt(10000); //Generates a random number to test
      
          
       System.out.println("Sample random integer is: "+x);
       System.out.println("The reversed integer is: "+reverseDigit(x));
       //Program User Input to method
       Scanner in=new Scanner(System.in);
      
       System.out.print("Enter an integer: "); //asks for input integer
       int num=in.nextInt();
       String sample=""+num;
       char ch= sample.charAt(0);
       if(ch=='-')
       {
           sample=sample.substring(1);
           int num1=Integer.parseInt(sample);
           System.out.println("The reversed integer is: -"+reverseDigit(num1)); //prints reversed integer
       }
       else
       {
           System.out.println("The reversed integer is: "+reverseDigit(num)); //prints reversed integer
       }
   }
   //reverseDigit method
   public static int reverseDigit(int integer)
   {
       int reverseInteger=0;
       while(integer>0)
       {
           reverseInteger=10*reverseInteger+(integer%10); //reverses the integer
           integer/=10;
       }
       return reverseInteger;
   }
}

Sample Output:

Sample random integer is: 1735
The reversed integer is: 5371
Enter an integer: -1234
The reversed integer is: -4321

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