What does '\0' mean here?

[ferrari5107]

int main(void)
{

char cAlphabet[] = {'I',' ', 'k','n','o','w',' ','a','l','l',' ','a','b','o','u','t',' ','p','r','o','g','r','a','m','i','n','g','!','\0'};
string sAlph(cAlphabet);
vector<string>sPhrase;
int size = sAlph.length();

................................

}

and


int main(void)
{

char cAlphabet[] = {'I',' ', 'k','n','o','w',' ','a','l','l',' ','a','b','o','u','t',' ','p','r','o','g','r','a','m','i','n','g','!'};
string sAlph(cAlphabet);
vector<string>sPhrase;
int size = sAlph.length();

................................

}

First one give size of 28, second one gives size of 39. Only difference is addition of \0 in the array of first program.

So What does \0 mean? and what does it do?

[Disch]

'\0' is the null termination character. It marks the end of the string. Without it, the computer has no way to know how long that group of characters goes. When you print/copy/whatever a string, it just keeps printing/copying chars until it finds that null char... that's when it knows to stop.



EDIT:

On a side note, '\0' actually isn't special or anything, it's just an numerical escape sequence. IE: '\0' is just the literal number 0. Just like '\1' is the literal number 1.

I just felt like mentioning that for whatever reason. It's not important.

/EDIT

[ascii]

its quite useful if you want to iterate through each character of a string by just going to the next character until a \0 is found. also note that when using double quotes "" they automatically add the \0. so

char cAlphabet[] = "I know all about programming!";

is the same as

char cAlphabet[] = {'I',' ', 'k','n','o','w',' ','a','l','l',' ','a','b','o','u','t',' ','p','r','o','g','r','a','m','i','n','g','!','\0'};

and nowhere near as annoying to type

p.s. you mispelled programming :o