I’m reading the introduction section of the K&R book on C. To see what code format generates errors, I tried splitting printf("hello world!"); into different lines, as shown below. The problem is, I don’t know if my results are implementation-independent. I used the GCC compiler.
What do C standards say about multiline expression? How do compilers deal with them?
/*
printf("hello wor
ld!\n");
*/
/*
printf("hello world!
\n");
*/
printf("hello world!\
n");
/*
printf("hello world!\n
");
*/
printf("hello world!\n"
);
printf("hello world!\n")
;
The commented-out expressions generate errors, while the remaining ones do not.
The behavior of the third expression was unexpected. Usually " needs to be terminated on the same line but the third expression works.
Third expression:
printf("hello world!\
n");
Output to console:
hello world! n
It seems like \ can be used to split a string into multiple lines, but the space before n"); is included as part of the string. Is this a standard rule?
>Solution :
118 2. Each instance of a backslash character (\) immediately followed by a new-line character is deleted, splicing physical source lines to form logical source lines.
So basically writing
printf("hello world!\
n");
is identical to writing
printf("hello world! n");