The distinction between string constants and character arrays

First, let's take a look at the program, which is about the implementation of the String function strcat () function:

#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#define MAX
Char *my _strcat (char *dest, const char *src)
{
    char * ret = dest;
    ASSERT (dest);
    ASSERT (SRC);
    while (*dest)
    {
        dest++;
    }

    while (*dest = *src)
    {
        dest++;
        src++;
    }
    return dest;
}
int main ()
{
    char Arr1[max] = "ABCD";
    Char *arr2 = "ABCD";
    My_strcat (arr1, arr2);
    printf ("%s\n", arr1);
    System ("pause");
    return 0;
}

Here we have a question:

Char Arr1[max] = "ABCD";
    Char *arr2 = "ABCD";

This two is why this should be initialized.

In fact, the first line is initialized with a character array.

Char Arr1[max] = "ABCD";

Although he looks like a string constant, it's not, he's just another way of initializing the list. He is differentiated according to the context in which they are located, and when used to initialize a character array, he is an initialization list, and elsewhere, he represents a string constant

And the second sentence:

Char *arr2 = "ABCD";

The initialization here is a string constant.

These two initializations look very much alike, but they have different meanings, the former initializing the elements of a character array, and the latter being a true string constant. This pointer variable is initialized to the storage location that points to the string constant.