Question

Whats the difference(,adv/disadv) in the two ways of initialing a string variable in ios?

NSString *var = @"value" and NSString *var =[ [NSString alloc] initWithString:@"value"]

Answer 1

The code:

NSString *var = @"value";

Creates an instance of NSCFConstantString which is created by the compiler and stored as part of the program’s data. It doesn’t respond to retain or release and can effectively be ignored for memory management purposes.

However the code:

NSString *var =[ [NSString alloc] initWithString:@"value"];

Allocates an NSString object and initialises it with the content of the constant string @"value". It must be released when no longer required but cannot be updated (it is immutable), so offers little over the first piece of code.