Thread: Am I right?

> char *s=”Hello”;

This is actually correct. This is valid. "char *s" means:

"s is a pointer to a character", or "a character pointer named s"

It is legal to do that assignment.
Keep in mind though that "Hello" becomes a string literal.

Quzah.

char s[]="Hello"; Yes
char s[]; No /*What will you do with it?*/
char s[6]; Yes
char s[5]="Hello"; No /*Run Time Error*/
char *s="Hello"; Yes

Originally posted by zahid
char s[]; No /*What will you do with it?*/
char s[5]="Hello"; No /*Run Time Error*/
[/B]

Allow me to elaborate on why neither of these declarations are valid.

char s[] tells the compiler you want to create an array of characters (a string), but it does not tell the compiler how much memory to reserve for the array. The compiler must know how much memory to set aside for your array, so this declaration fails. char s[]="Hello" works because of the initilization. The compiler knows what you want to put into the array (the characters 'H', 'e', 'l', 'l', 'o', '\0'), and sets aside enough memory.

char s[5]="Hello" might look fine to you. After all, the array 's' is five characters in length and the word "Hello" only requires five characters, so what's the problem? In C, strings are terminated with a null zero (the character '\0'). The null zero is a character, so it takes up just as much space as the 'H' or the 'e' in "Hello". char s[5] does not leave enough room for the null zero, so you are trying to initialize the array by putting something too large into it. Either of the following will work here:

Code:

char  s[]="Hello";
char  s[6]="Hello";

Originally posted by Salem
The 'problem' is that such an array cannot be used with some of the standard library string functions - but that's a different question.

Originally posted by DjGazUK
10. Indicate using ticks and crosses which of the following string variable declarations are valid and self-consistent.

I believe this makes it an invalid string (a perfectly good character array, but not a string). I suggest the student cross out char s[5]="Hello"; as invalid.