Declaration and definition of classes in OC Foundation--OC

Steps to design a class in OC:

First, the declaration of the class:

1. Keywords used [email protected] and @end

2. Class name

3. Inheriting NSObject

4. Properties

5. Method (behavior, declaration only)

II. realization (definition) class

1. Keywords used [email protected] and @end

2. Implementing the methods declared in @interface

3. Declaration and implementation of methods in a class be careful to start with the minus "-"

The parentheses in the 4.OC class cannot be used indiscriminately, and parentheses are used to enclose the type! --Remember!

Example: The following code declares and defines the class, the method in the class has no return value, no parameter

1*implementing the methods declared in @interface2*/3 4 #import<Foundation/Foundation.h>5 6 //declaration of the class7 @interfaceDog:nsobject8 //Properties9 {Ten     @public One     intSpeed ; A } -  - //just a statement . the- (void) run; -  - @end //Write @interface immediately after writing @end -  + //implementation of the Class (definition) - @implementationDog +  A //implementing the Run method at- (void) Run - { -NSLog (@"The speed of the%i dog ran up.", speed); - } - @end -  in intMain () - { toDog *dog = [dogNew]; +Dog->speed = -; -      the [dog run]; *      $     Panax Notoginseng     return 0; -}

The method name of the class in OC has the condition of the return value and the parameter:

1. One parameter corresponds to a colon

2. A colon is also part of the method name

1 /*2 Design a calculator class3 1. Class Name: Caculator4 2. Behavior (method):5 * Return to pi:3.146 * Calculates the square of a value7 * Calculation of two values and8  */9 Ten #import<Foundation/Foundation.h> One  A //Statement of the calculator - @interfaceCaculator:nsobject -  the //declaration of the method -- (Double) Pi;//method name Pi, return value type is double parenthesis enclosing type, no parameter -  - //-(Double) Pi: (int) ABC; //Method name pi: +  - //one parameter corresponds to a colon + //the colon is also part of the method name A- (Double) Pingfang: (Double) number;//method Name: Pingfang: at  - //method Name: sumofnum1:andnum2:--to enhance the readability of your code -- (Double) SumOfNum1: (Double) NUM1 andNum2: (Double) num2; - @end -  -  in intMain () - { toCaculator *CA = [caculatorNew]; +      -     //NSLog (@ "pi=%f", [CA PI]); the      *     //double d = [CA pingfang:4]; $     Panax Notoginseng     //NSLog (@ "4 squared =%f", d); -      the     Doublehe = [CA sumOfNum1:TenANDNUM2:5]; +  ANSLog (@"10+5=%f", he); the      +      -      $Caculator *CA2 = [caculatorNew]; $      -     return 0; - } the  - Wuyi //the implementation of the calculator the @implementationCaculator -  Wu //implementing the methods declared in @interface -- (Double) Pi About { $     return 3.14; - } -  -- (Double) Pingfang: (Double) number A { +     returnNumber *Number ; the } -  $- (Double) SumOfNum1: (Double) NUM1 andNum2: (Double) num2 the { the     returnNUM1 +num2; the } the  - @end

The difference between the function in OC and the OC object method:

1. Functions belong to the entire file, can be called anywhere in the file; Object methods belong to objects, only objects can call object methods

2. Object methods can only be declared between @interface and @end, and object methods can only be implemented between @implementation and @end.

The Declaration and definition of a function can be written anywhere, and the function cannot be owned by a class and belongs to only one file.

Declaration and definition of classes in OC Foundation--OC