Testing if a number is a Palindrome using different functions (C++)

Question

The code I am using is:

#include <iostream>
using namespace std;


int reverse (int number){
  int t = number, m = 0;
    do
    {
        m = m*10 + t%10;
    } while(t /= 10);

    return m == number;
}

bool isPalindrom(int number){
    bool Palindrom = reverse(number);
  if(Palindrom == true){
   return true;   
  } else { 
   return false;   
  }
    return 0; 
}

int main()
{
  int number;
  cout << "Please input a number " << endl;
  cin >> number;

  if(isPalindrom){
   cout << "This is a Palindrom" << endl;   
  } else {
    cout << "This is not a Palindrom" << endl;   
  }

}

The issue I am having is that isPalindrom is always evaluating to true. I believe it is because I am trying to set this up incorrectly. The program asks us to use the two functions bool isPalindrom(int number) and int reverse(int number). I'm just learning to use functions in C++ so i'm not to sure what I should do. Should I have reverse return the numbers flipped self (m) then in palindrom compare number to m and if it evaluates to true, it will return true. Then in the main check with an if statement to see if isPalindrom is true/false.

Answer 1

You are not calling the function correctly.

 if(isPalindrom){
    cout << "This is a Palindrom" << endl;   
 } else {
    cout << "This is not a Palindrom" << endl;   
 }

To call it you have to supply a parameter like this

if (isPalindrom(number)) {
    ....

In your code isPlanindrom is (I believe, but actually it does not matter if I am right on this point) a function pointer and because it is in the condition of if it gets converted to a bool, which is true always.

PS: I just noticed that I was too fast in writing the answer. I just saw this one problem and didnt look at the rest of the code. It seems like you need to learn about very basics which would be too much to cover here in an answer. My suggestion: Get a book and rtfm :P