Question

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Sizeof string literal

On my windows7 mingw environment, I tried this:

char str[] = "hello";

The value of sizeof(str) is 6, not 4 or 8.

How can this happen?

Answer 1

sizeof(str) returns the number of bytes in the string which includes the terminating null character. I.e., "hello\0" makes for 6 bytes in your array.

If instead you had had

char* str = "hello";

then sizeof(str) would have returned the number of bytes in the pointer str (4 for 32-bit systems).

You may find this SO question Why does sizeof return different values for same string in C? of interest.