Look at the following piece of code in C++:
char a1[] = {'a','b','c'};
char a2[] = "abc";
cout << sizeof(a1) << endl << sizeof(a2) << endl;
Though sizeof(char)
is 1 byte, why does the output show sizeof(a2)
as 4 and not 3 (as in case of a1
)?
C-strings contain a null terminator, thus adding a character.
Essentially this:
char a2[] = {'a','b','c','\0'};
That's because there's an extra null '\\0'
character added to the end of the C-string, whereas the first variable, a1
is an array of three seperate characters.
sizeof
will tell you the byte size of a variable, but prefer strlen
if you want the length of a C-string at runtime.
For a2, this is a string so it also contains the '\\n'
Correction, after Ethan & Adam comment, this is not '\\n' of course but null terminator which is '\\0'
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