Question

What I need:

Create a new program named Reverse4 and declare four integer variables with the values 23, 45, 55, and 67.

Add a method named Reverse that reverses the positions of four integer variables. The Reverse method should accept the variables as references.

Write a Main() method that displays the four variables both before and after reversing them to ensure the method works correctly.

What I have:

using System;
class Reverse4 {

public static void reverse(ref int num1, ref int num2, ref int num3, ref int num4)
{
int temp;

temp = num1;
num1 = num4;
num4 = temp;

temp = num2;
num2 = num3;
num3 = temp;
}

public static void Main (string[] args) {
int a = 23;
int b = 45;
int c = 55;
int d = 67;

Console.WriteLine("Before swap");
Console.WriteLine(a + ", " + b + ", " + c + ", " + d);

/* calling a function to swap the values */
reverse(ref a, ref b, ref c, ref d);

Console.WriteLine("After swap");
Console.WriteLine(a + ", " + b + ", " + c + ", " + d);
}
}

Error I get:

Compilation failed: 1 error(s), 0 warnings

NtTest444c819b.cs(13,16): error CS0117: `Reverse4' does not contain a definition for `Reverse'
Reverse4.cs(2,7): (Location of the symbol related to previous error)

Answer 1

Declare the class Reverse4 as public and its working fine

using System;
public class Reverse4 {

public static void reverse(ref int num1, ref int num2, ref int num3, ref int num4)
{
int temp;

temp = num1;
num1 = num4;
num4 = temp;

temp = num2;
num2 = num3;
num3 = temp;
}

public static void Main (string[] args) {
int a = 23;
int b = 45;
int c = 55;
int d = 67;

Console.WriteLine("Before swap");
Console.WriteLine(a + ", " + b + ", " + c + ", " + d);

/* calling a function to swap the values */
reverse(ref a, ref b, ref c, ref d);

Console.WriteLine("After swap");
Console.WriteLine(a + ", " + b + ", " + c + ", " + d);
}
}