How to split a string literal across multiple lines in C / Objective-C?
There are two ways to split strings over multiple lines:
Using \
All lines in C can be split into multiple lines using \.
Plain C:
char *my_string = "Line 1 \ Line 2";
Objective-C:
NSString *my_string = @"Line1 \ Line2";
Better approach
There's a better approach that works just for strings.
Plain C:
char *my_string = "Line 1 " "Line 2";
Objective-C:
NSString *my_string = @"Line1 " "Line2"; // the second @ is optional
The second approach is better, because there isn't a lot of whitespace included. For a SQL query however, both are possible.
NOTE: With a #define, you have to add an extra '\' to concatenate the two strings:
Plain C:
#define kMyString "Line 1"\ "Line 2"
There's a trick you can do with the pre-processor.
It has the potential down sides that it will collapse white-space, and could be confusing for people reading the code.
But, it has the up side that you don't need to escape quote characters inside it.
#define QUOTE(...) #__VA_ARGS__const char *sql_query = QUOTE( SELECT word_id FROM table1, table2 WHERE table2.word_id = table1.word_id ORDER BY table1.word ASC);
the preprocessor turns this into:
const char *sql_query = "SELECT word_id FROM table1, table2 WHERE table2.word_id = table1.word_id ORDER BY table1.word ASC";
I've used this trick when I was writing some unit tests that had large literal strings containing JSON. It meant that I didn't have to escape every quote character \".
You could also go into XCode -> Preferences, select the Indentation tab, and turn on Line Wrapping.
That way, you won't have to type anything extra, and it will work for the stuff you already wrote. :-)
One annoying thing though is...
if (you're long on indentation && short on windows) { then your code will end up squished against th e side li k e t h i s}