When/Why is '\0' necessary to mark end of an (char) array?
So I just read an example of how to create an array of characters which represent a string.
The null-character \0 is put at the end of the array to mark the end of the array. Is this necessary?
If I created a char array:
char line[100];
and put the word:
"hello\n"
in it, the chars would be placed at the first six indexes line[0] - line[6], so the rest of the array would be filled with null characters anyway?
This books says, that it is a convention that, for example the string constant "hello\n" is put in a character array and terminated with \0.
Maybe I don't understand this topic to its full extent and would be glad for enlightenment.
Answer
The \0 character does not mark the "end of the array". The \0 character marks the end of the string stored in a char array, if (and only if) that char array is intended to store a string.
A char array is just a char array. It stores independent integer values (char is just a small integer type). A char array does not have to end in \0. \0 has no special meaning in a char array. It is just a zero value.
But sometimes char arrays are used to store strings. A string is a sequence of characters terminated by \0. So, if you want to use your char array as a string you have to terminate your string with a \0.
So, the answer to the question about \0 being "necessary" depends on what you are storing in your char array. If you are storing a string, then you will have to terminate it with a \0. If you are storing something that is not a string, then \0 has no special meaning at all.