指针数组，改变指针元素

Question

If I declare an array of pointers like that:

    char* arr[5] = {"Mercury",
    "Mercury",
    "Venus",
    "Earth",
    "EArth"};

Can I then change sings in those pointers? I have tried doing something like that

*(*(arr + 1) + 1) = 'i';

but it doesn't work, I get memory dump. Is there a way to do that or I have to declare it differently?

Answer 1

Is there a way to do that or I have to declare it differently?

char* arr[5] = {"Mercury", "Mars", "Venus", "Earth", "Pluto"};

arr is an array of 5 char pointers to string literals. Any attempt to modify a string literal invokes undefined behavior, so you can´t modify them.

If you want to modify the content you need fe to define them as two-dimensional array of char s:

char arr[5][10] = {{"Mercury"}, {"Mars"}, {"Venus"}, {"Earth"}, {"Pluto"}};

and use

strcpy(arr[0], "Uranus");

size_t len = strlen(arr[0]);  
for(size_t i = 9; i > (len + 1); i--)  // To remove all left characters from prev. string.
{
    a[0][i] = '\0';
}