Dark Horse Programmer---objective-c basic learning---get and set methods

Get and set methods in Objective-c

Set method

1. Function: Provide a method to set the value of member variables to the outside world, can be in the method to face the parameters of the corresponding filter

2. Naming conventions:

1> method name must begin with set

2> set followed by the name of the member variable, the first letter of the member variable must be capitalized

3> return value must be void

4> must receive a parameter, and the parameter type is consistent with the member variable type

The name of the 5> parameter cannot be the same as the member variable name

-(void) Setage: (int) newage;

Get method

1. Function: Returns the member variable inside the object

2. Naming conventions:

1> must have a return value, and the return value type must be the same as the member variable type

The 2> method name is the same as the member variable name

3> does not need to receive any parameters

- (int)age;

- (void)study;

Defines a student class that has a member variable, age, and the corresponding Get\set method.

1.student.h

1 #import <Foundation / Foundation.h>
  2 
  3 @interface Student: NSObject
  4
  5 {
  6 // Don't use @public as a member variable
  7 int age;
  8 }
  9 
10-(void) setAge: (int) newAge;
11-(int) age;
12
13 @end 

1> defines a member variable age in line 7th, which is @protected permission, so the outside world cannot access it directly

2> the Set method and the Get method for the age variable in line 10th and 11, respectively

2.student.m

 
 
1 #import "Student.h"
 2 
 3 @implementation Student
 4 
 5 - (void)setAge:(int)newAge {
 6     age = newAge;
 7 }
 8 
 9 - (int)age {
10     return age;
11 }
12 
13 @end

1> implements the Set method on line 5th

2> implemented the Get method on line 9th

3.main.m

Put the well-defined student class in the main function

1 #import <Foundation / Foundation.h>
  2 #import "Student.h"
  3
  4 int main (int argc, const char * argv [])
  5 {
  6 @autoreleasepool {
  7 Student * stu = [[Student alloc] init];
  8         
  9 // Set the value of age
10 [stu setAge: 10];
11
12 // Get the value of age
13 int age = [stu age];
14
15 NSLog (@ "age is% i", age);
16
17 [stu release];
18}
19 return 0;
20} 

1> header file containing student in line 2

2> create student object on line 7th, release student object on line 17th

3> call the Set method on line 10th to set the value of age

4> call the Get method on line 13th to get the value of age

5> outputs the value of age on line 15th, and the output is as follows:

----------57.345 a. Out [2643:  707isten

This is a simple use of the OC Traditional get method and set method.

Dark Horse Programmer---objective-c basic learning---get and set methods