I still don't know, when my string in c program contain null-terminated and when it doesn't contain.
Sample of my code
...
float t0 = 2.43, t1 = 3.42, t2 = 1, t3 = 10.9;
...
printf("%.2f %.2f %.2f %.2f", t0, t1, t2, t3);
...
If i use printf like in my code, does c program will automatically add null-terminated at the end of string that printed or no?
Q: If i use printf like in my code, does c program will automatically add null-terminated at the end of string that printed or no?
A: No. printf() does not typical print the terminating null character '\0'. Instead "%.2f %.2f %.2f %.2f" causes output like "1.12 2.23 3.34 4.45" with the last character printed as '5'.
[Edit]
The format "%.2f %.2f %.2f %.2f" is a string which ends with a null terminator '\0'. The printed output of printf() did not print a '\0'. The null terminator '\0' in the format signals to printf() to stop. The null terminator '\0' itself is not printed.
Note: In C, a C string always has a terminating null character '\0'. If an array of char does not contain one, it is not a string. So the output of printf() in the above example is not a string, but simply a series of characters.
The 1st argument to
printf("%.2f %.2f %.2f %.2f", ...
is a string literal ("%.2f %.2f %.2f %.2f") and yes, also string literals are 0-terminated.
Effectively yes, had you declared char format[]="%f %f\n";
Using gdb or adding some research code you'd be able to see the nul byte terminating the string.
The answer to If i use printf like in my code, does the string that printed contain null character at the end? is yes it contains but you will not see it in printf.
The null terminator indicates the end of a string when represented as an array of characters. When using the printf function you pass a pointer to the beginning of the string as a parameter and it will print the string until the NULL terminator.
NULL != null; null== NUL == 0
printf()will help. Theprintffunction sends the resulting output tostdout. No terminator is emitted. Or were you thinking ofsprintf()?printf, and whether it finishes with a null-terminator (which it doesn't). So far, no answer below seem to have picked up on that. My cheap-glass, out-of-round, poor excuse for a crystal ball tells me the question is eventually related to stdout redirection and whether that output adds a terminator to the target device.