Why is max length of C string literal different from max char[]?

Question

Clarification: Given that a string literal can be rewritten as a const char[] (see below), imposing a lower max length on literals than on

Answer 1

Sorry about the late answer, but I'd like to illustrate the difference between the two cases (Richard J. Ross already pointed out that they're not equivalent.)

Suppose you try this:

const char __THE_LITERAL[] = { 'f', 'o', 'o', '\0' };
const char* str = __THE_LITERAL;
char *str_writable = (char *) str;  // Not so const anymore
str_writable[0] = 'g';

Now str contains "goo".

But if you do this:

const char* str = "foo";
char *str_writable = (char *) str;
str_writable[0] = 'g';

Result: segfault! (on my platform, at least.)

Here is the fundamental difference: In the first case you have an array which is initialized to "foo", but in the second case you have an actual string literal.

On a side note,

const char __THE_LITERAL[] = { 'f', 'o', 'o', '\0' };

is exactly equivalent to

const char __THE_LITERAL[] = "foo";

Here the = acts as an array initializer rather than as assignment. This is very different from

const char *str = "foo";

where the address of the string literal is assigned to str.