not all codepaths return a value

vasanth krishna

13y2.1kVisual Basic .NET

Error : "not all code path return a value"

what's the problem in this program..the program is to find the given number is a palindrome or not

class Program

{

static void Main(string[] args)

{

int number;

number = Convert.ToInt32(Console.ReadLine());

int rev = rev1(number);

Console.WriteLine(rev);

if (rev == number)

Console.WriteLine("is a palandrome");

else

Console.WriteLine("not a palandrome");

Console.ReadLine();

}

private static int rev1(int number)

{

int sum = 0;

if(number==0)

{

int j = number % 10;

sum = sum * 10 + j;

int c = sum;

rev1(number / 10);

return sum;

}

3 Replies

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Vulpes13y ago
Accepted answer
Just noticed your other thread where you're asking for this to be done using recursion:

using System;

class Program
{
static void Main(string[] args)
{
int number;
number = Convert.ToInt32(Console.ReadLine());
int rev = rev1(number);
Console.WriteLine(rev);
if (rev == number)
Console.WriteLine("is a palandrome");
else
Console.WriteLine("not a palandrome");
Console.ReadLine();

}

private static int rev1(int number)
{
return rev2(number, 0);
}

private static int rev2(int number, int sum)
{
if (number == 0) return sum;
int j = number % 10;
sum = 10 * sum + j;
number = number / 10;
return rev2(number, sum);
}
}
0
Vulpes13y ago
Another problem you have is that the program doesn't actually work!

However, if you change your rev1 method as follows then it should work fine. There's no need for recursive calls.

class Program
{
static void Main(string[] args)
{
int number;
number = Convert.ToInt32(Console.ReadLine());
int rev = rev1(number);
Console.WriteLine(rev);
if (rev == number)
Console.WriteLine("is a palandrome");
else
Console.WriteLine("not a palandrome");
Console.ReadLine();

}
private static int rev1(int number)
{
int sum = 0;
while (number > 0)
{
int j = number % 10;
sum = sum * 10 + j;
number = number / 10;
}
return sum;
}
}
0
Vulpes13y ago
If you move 'return sum;' outside of the 'if' statement then it should compile.

Also the line int c = sum; appears to be redundant:

private static int rev1(int number)
{
int sum = 0;
if(number==0)
{

int j = number % 10;
sum = sum * 10 + j;
//int c = sum;
rev1(number / 10);
//return sum;
}
return sum;
}
0