Pointers and C-Strings

[McClapYourHands]

Hello everyone!

Well I, McClapYourHands, am utterly confused. I am working on a class project that is relating C-strings and pointers.

Part of the problem, is that the wording on this assignment confuses me to no end. Secondly, me and c-strings just don't get along and I am always mixing up what you can/cannot do.

The goal of this code is to do 3 things.
1) modify the given code to enact the next 2 goals.
2) Your program should ask the user for the size of the C-string to be entered, then use new to create the two pointers (C-strings).
3) write a function that reverses a string, to practice using pointers

Problems I'm running into/questions I cannot answer.

1. initially the STRINGSIZE was 'const char' type but then I couldn't use it in IntArray. but ofcourse, I'm running into a problem when using it to define the size of oldCString. ..... what am I not realizing??

2. I've gotten the reverse function to work... slightly. I get the words to be reversed but all sorts of weird symbols before and after it. I know i'm misunderstanding something basic.

My brain is not grasping these basic concepts, so I'm looking to anyone to help explain things differently. Thanks in advance!

code bellow

*****************************************************************************

 #include <iostream>
#include <cstring>
#include <cstdlib>
using namespace std;

typedef int* IntArrayPtr;

int Reverse(char * destination, const char * source, int num);
int main() 
{
    int STRINGSIZE;
    char oldCString[];
    char newCString[STRINGSIZE];
    cout << "Enter the size of the C-string you are using:\n";
    cin >> STRINGSIZE;
    IntArrayPtr a;
    a = new int[STRINGSIZE];

    cout << "Enter the C-string you would like reversed. \n";
    cin >> oldCString;
    cout << endl << endl;
    cout << "oldCString: " << oldCString << endl;
    cout << "newCString before changing: " << newCString << endl;

    
    Reverse(newCString, oldCString, STRINGSIZE); // testing your function...

    cout << "newCString after Reverse: " << newCString << endl;
    return 0;
}

// Reverses a C-string passed in (source), and places the reversed 
//    C-string into (destination).
// (num) should represent the maximum valid length of (destination).
// If no null-zero character is found in (source) within (num-1) 
//    characters,the function will only read up to (num-1) characters
//    from (source), and then copy the reversed characters to 
//    (destination) and append a null-zero to the end of it.
// The function will return the number of characters placed into 
//    (destination), including the null-zero.
// The function MUST use pointer notation (not array notation) inside
//    it.  However, you might find it useful to use array notation
//    temporarily while developing the function, and then replace
//    with pointer notation before turning in the assignment.
int Reverse(char * destination, const char * source, int num)
{
    for (int i = 0; i < num; i++)
    {
        destination[i] = source[i];
        destination[i] = source[num - i - 1];
       cout << destination[i];
    }

    return 0;
}

[AbstractionAnon]

Line 11: STRINGSIZE is an uninitialized variable.

Line 12: This array has no dimension.

Line 13: How much space do think is being allocated using an uninitialized variable? This line is not valid C++. In C++ array dimensions must be known at compile time.

Line 16-17: You're creating an array of ints. For what purpose? You never use this array.

Line 23: You're printing newCString before anything has been placed in it.

Your assignment says to use new for both oldCString and newCString, which you are not doing.

Line 49: What's the purpose of this line? You overwrite what you store is destination[i] on the next line.

The stated conditions of your Reverse function are not met.
Line 35: "If no null-zero character is found " implies you should be checking for a null character. You're not.

Line 39-40: You're not returning the number of characters placed in destination. You're returning 0.