Convert between C string and NSString

Declare and define a string

// C string
char *foo;
// NSString
NSString *bar;
foo = "this is a C string";
bar = @"this is an NSString";

Convert

const char *foo = "Blah blah";
NSString *bar;
// Create an NSString from a C string
bar = [NSString stringWithUTF8String:foo];

// Create a C string from an NSString
foo = [bar UTF8String];