How to change dynamic array in function using C? [duplicate]

Question

I want to create void function that will change existing dynamic (or static) array. How this can be implemented in C and C++? How to properly pass arguments to such functions? For example i want to reverse char array

//function that reverse the string
void reverseString(char* str)
{
    char t;
    int i, j;
    for (j = 0; str[j] != '\0'; j++)
    {
    }
    j -= 1;
    for (int i = 0; i < j; i++, j--)
    {
        t = str[i];
        str[i] = str[j];
        str[j] = t;
    }
}

int main()
{
    char* name = "Ani?321";
    reverseString2(&name);
    printf("%s", name);
}

running this code: Exception thrown at 0x796028BC (ucrtbased.dll) in Strings.exe: 0xC0000005: Access violation reading location 0x00E87B51.

When i changing function parameter from char* to char** -> Run-Time Check Failure #2 - Stack around the variable 'str' was corrupted. (pointing to the closing curly bracket of the main function)

Answer 1

Well, you have declared a string literal which you can't modify. Declare it like this instead char name[] = "Ani?321";

Answer 2

You have two major problems:

1. Your pointer name is pointing to a literal string. Such strings can't be modified, and any attempt to do so leads to undefined behavior. You solve this issue by using an array instead:

   char name[] = "Ani?321";
   

2. The second problem is that you pass a pointer to the pointer to your function. The type of &name (in your current code) is char **, which is not the correct type and definitely not the correct pointer. You should pass plain name as argument (which will also work when you solve the first problem).