Question

I’ve cut out a lot of the code to make it easier to read. Specifically I’m trying to rewrite strcat

#include <iostream>
using namespace std;

char MYstrcat(char string1[],char string2[]);

int main()
{
    char letter, letter_ans, again;
    const int SIZE = 80;
    char string1 [SIZE];
    char string2 [SIZE];

getting input for the character arrays

    cout << "Enter the first string: ";
    cin >> string1;
    cout << "Enter the second string: ";
    cin >> string2;
    letter_ans=MYstrcat(string1, string2);
    cout << letter_ans;

    cin.get(); cin.get();
    return 0;
}

this is my version of the strcat function

char MYstrcat(char string1[],char string2[])
{ 
    int i = 0; //Counters
    int j = 0;

    //Read until null character is encountered then append.
    while (string1[i] != '\0')
    {
        i++;
    }
    while (string2[j]!= '\0'){
        string1[i] = string2[j];
        i++;
        j++;
    }
    string1[i]='\0'; // Place a null character in string2.

i get the error in this next line: invalid conversion from ‘char*’ to ‘char’

    return string1;
}

Answer 1

char MYstrcat(char string1[],char string2[]); // returns a single character
char *MYstrcat(char string1[],char string2[]); // returns a pointer to a string that can be used like string1[] and string2[]

Likewise,

char letter_ans;    // this gives space for a single char, like int int_ans;
char *letter_ans;   // this makes a pointer to an array of char's, the proper return type

However, since you are returning string1, it may be possible that you don’t even want to use a return type. If you declare your function as so:

void MYstrcat(char *string1,char *string2);

It will operate directly on string1, leaving no need to return a pointer to it.