Statements and definitions such as "Good Programmer's note sharing" obj-c

<a href= "http://www.goodprogrammer.org/" target= "blank" >ios training </A>------My obj-c language notes, looking forward to communicating with you!

As a result of the basic test, the obj-c still do not know very well, do a step confused (in fact, I think there will be only C related problems-_-#), there are some classes of inheritance, declaration, definition aspect is a problem, because before the C + + to object-oriented have a certain understanding, First look at the information in advance to see objc-c this piece of knowledge.

 Declaration of the class:
1 #import<Foundation/Foundation.h>2 3 @interfacePerson:nsobject4 {5   @public:6     intAge ; 7 }8-(void) func;9 @end
implementation of the class: Ten #import"Person.h" One  A @implementation Person --(void) func{ -NSLog (@"I ' m very hungry now"); the } - @end

Declaration: @interface Class Name: Parent class Name {} @end

Definition: @implement {} @end

NSObject is a direct or indirect parent class of any class

Member variable access permission modifiers: @public, @protected(default), @private

Member Methods and class methods: "-" is decorated as a member method, "+" is a class method (class methods cannot contain instance variables, or direct-to-compile-time errors)

When you want to expose a member method, declare it between the @interface class name: Parent class Name {} @end, and be able to call outside the class

Common errors:

(1) @interface @end and @implementation @end cannot be nested with

(2) Only the declaration of the class has no implementation of the class

(3) Missing write @end

(4) member variable not written in {}

(5) The declaration of the method is written in {}

(6) method cannot be called like a function

(7) member variables and methods can not be modified with static and other keywords, do not confuse the C language ( static variable generation method: The @interface class Name: The parent class name {} @end the member variable is static decorated, You need to declare a global static variable in the @implement @end implementation file, and then write the Get method and set method of the static variable to be called outside the class, so that the static variable can be generated.

(8) The implementation of the class can be written behind the Mian function, as long as there is a declaration before use can

Statements and definitions such as "Good Programmer's note sharing" obj-c