Objective-c plus minus sign-+

"The plus sign stands for static" is a wrong statement. People who may express it like you actually mean: "The method of leading plus sign is equivalent to static method in Java".

In Oc, methods are divided into class methods and instance methods.

The method with a plus sign (+) is a class method. Such methods can be called directly with the class name. Its main purpose is to create an instance. Some people call it a factory method for creating instances.

The method preceded by a minus sign (-) is an instance method, which must be called using an instance of the class.

As you said, declaring a member variable with a plus sign is completely misunderstood. To declare a member variable as static, you must use the static keyword.

Objective-c plus minus sign-+