What is the difference between the + and - sign in Objective-C

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What is the difference between the + and - sign in Objective-C

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#1 by (9 votes)

5

I wanted to know what the difference is when I create a method using the "+" and "-"?

And also when to use and why to use, I usually only use the "-", but I do not know how to use the method with "+".

Thank you.

ios objective-c

asked by anonymous 21.07.2014 / 04:21

1 answer

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score 9 · Accepted Answer

Thus, methods with - are instantiation methods, that is, you can only call these methods through an instance of the class:

NSString *instanciaString = [[NSString alloc] init];
[instanciaString length];

And methods with the + prefix are class methods. These methods do not need an instance to be called, you can call directly from the class, for example:

[NSString stringWithString:@"Hello World"];