Please take the following:
char buffer[512];
memset(buffer, 0, sizeof(buffer));
sprintf(&buffer[0],\"This Is The Longest String In the World that in tex
The newline continuation takes into account any whitespace within the code.
You can take advantage of string literal concatenation for better readability:
sprintf(buffer, "This Is The "
"Longest String In the World "
"that in text goes on and..");
Using \ you'll need to begin the continuation of your string at column 0:
sprintf(buffer, "This Is The \
Longest String In the World \
that in text goes on and..");