Objective-C difference between class and instance of that class -

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could explain me difference between class , instance of class. if can use 1 instance of class in program, can use class instance , change (-) (+) in methods declaration. difference between class , instance methods. thanks

this seems several questions:

  1. what difference between class , instance of class?
  2. what if can use 1 instance of class?
  3. what difference between class , instance methods?

first, difference between class , instance of class class specification instance. class there, must create instance use instance methods of class. class creates instances , gives them methods.

second, "if can use 1 instance of class in program" situation never come up. can make many instances of class want (hardware permitting).

third, difference between class , instance method while must create instance use instance method, class methods useful functions class offers without creating object class. instance methods operate on properties/fields of specific instances, while class methods merely accept input , return values independent of instances.


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