C++ statements can be broken into more than a single line. However, you cannot break literal strings such as printf() format string, macros, or literals. When you need a long string, you can use the continuation marker \ (backslash) before a line break:
#define MESSAGE "a very long message that cannot fit into \
a single line. It may be broken more than once \
like that"
printf ("%10.10ld \t %10.10ld \t %s\
%f", w, x, y, z );
The preprocessor scans the source file before compilation and concatenates lines that are broken by a continuation marker. Thus, the compiler sees such lines as if they were typed without a break. Note that the line break (a hard return/enter) should appear immediately after the backslash.