Question

Hello can you give me an example of the usage of this method

+(NSString *)description

Do I use description with an instance of a NSObject (any kind of object) or NSString?

or do I use without an instance, directly using NSObject (any kind of object) or NSString?

Answer 1

The description of the instance gives you information about the specific instance you have created.

– (NSString *)description;

NSString *string = [NSString alloc] initwithString:@"aString"]];
[string description];

Gives you information about this instance (location in memory etc)

On the other side:

+ (NSString *)description;

[NSString description];

Gives you information about the class NSString.

The same rules apply to all NSObject subclasses and other classes that conform to NSObject protocol such NSArray, NSDictionary *NSProxy* etc