IOS 2 Setter and getter

Today the main learning of setter and getter use method, according to yesterday's learning content, first we want to create a project, in addition to create a person class!

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Create a few instance variables in the person class in Person.h, declaring the setter and getter method "on code" who the DARE code is!

#import <Foundation/Foundation.h>

/*

Instance variable visibility

[Email protected] public visibility : Access is available both inside and outside the class , because external access is also available , so he destroys the encapsulation nature of the class .

[email protected] private visibility : Only the current class is accessible, the subclass is inaccessible, and because the subclass is inaccessible, the inheritance of the class is broken .

[Email protected] protected visibility: The current class and subclasses are accessible . ( is the default ) is also the most suitable for use !

*/

@interface Person: nsobject

{

defining instance variables for the person class

nsstring *_name;// name belongs to string, so use nsstring and take *

nsstring *_sex;// sex belongs to string, so use nsstring and take *

Nsinteger _age;// Age is constant, so with int type, Nsinteger is the constant in OC, no need to take *

cgfloat _weight;// weight data constant, Cgfload equivalent to Fload, so no need to take *

}

Initialize method

-(ID) init;

Custom initialization method form : Initwith + interface part of the parameters for example :

-(ID) initwtihname: (nsstring *) name

Sex: (nsstring *) Sex

Age: (Nsinteger) Age // parameter type not with *

Weight: (cgfloat) weight; // parameter type not with *

Method declaration Greeting

-(void) sayhi;

Set setter method for each instance variable "uniform"

The format of the setter method is with the set header + instance variable (with the underscore , and the first letter capitalized ):(parameter type nsstring) parameter name

-(void) SetName: (nsstring *) name sex: (nsstring *) Sex Age: (Nsinteger) Age Weight: (cgfloat) Weight;

Set setter method "separate" for each instance variable

-(void) SetName: (nsstring *) name;

-(void) Setsex: (nsstring *) sex;

-(void) Setage: (nsinteger) age;

( return value) set ( parameter name) ( parameters type) (argument name )

-(void) Setweight: (cgfloat) weight;

Set the getter method for each instance variable that sets the setter method individually

Getter Format : The return value is the type of the corresponding instance variable , and the method name removes the underscore from the instance variable name

-(NSString *) name;

-(NSString *) sex;

-(Nsinteger) age;

-(cgfloat) weight;

/* It 's best to write setter and getter methods together for example:

-(void) SetName: (NSString *) name;

-(NSString *) name;

*/

@end

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In the person.m file, implement the Init method to implement the setter and getter method "on code" to ask who the code is!

#import "Person.h"//here do not misunderstand is in Person.h, this is person.m file

@implementation Person

Initialize the initial assignment for each instance

-(ID) init

{

_name = @ "Jack";

_sex = @ "male";

_age = +;// constant type, so do not use @ "

_weight = 160; //In the same vein as Age

return self;

}

Calling the process of the parent class system initialization

-(ID) initwtihname: (nsstring *) name sex: (nsstring *) Sex Age: (Nsinteger) Age Weight: (cgfloat) Weight

{

Self = [super Init]; calling a method of the parent class

if (self) {// if the method of the parent class is called

_name = name;//_name is the parameter in the top init , name is the name after initwithname

_sex = sex; When the name is passed to the new value in the main function, the _name equals the new name.

_age = age;

_weight = weight;

}

return self;

}

implementation of ========setter (Assignment) and getter ( value) methods ========//

Implementation of the method

-(void) Sayhi

{

NSLog(@ " people have the function of greeting "); Here is a concrete implementation of the methods declared in Person.h !

}

Implement Setter (Assignment ) method for each instance variable "unified"

Implement getter (value ) method for each instance variable "unified"

-(void) SetName: (nsstring *) name sex: (nsstring *) Sex Age: (Nsinteger) Age Weight: (cgfloat) Weight

{

_name = name;

_sex = sex;

_age = age;

_weight = weight;

}

Implement Setter (Assignment ) method for each instance variable "separately"

Note : Each method is implemented with the Person.h declared in the one by one corresponding to the Pro !

-(void) SetName: (nsstring *) name

{

_name = name;// Assigns the value of the incoming name to _name; Maybe a little around, think about it .

}

-(void) Setsex: (nsstring *) Sex

{

_sex = sex;

}

-(void) Setage: (nsinteger) Age

{

_age = age;

}

-(void) Setweight: (cgfloat) weight

{

_weight = weight;

}

Implement getter (value ) method for each instance variable "separately"

Note : Each method is implemented with the Person.h declared in the one by one corresponding to the Pro !

-(nsstring *) The Getter method implementation of name//name

{

return _name;

Return to the top init in the _name below the same method.

}

-(nsstring *) Sex//sex getter method implementation

{

return _sex;

}

-(Nsinteger) Age//age Getter method implementation

{

return _age;

}

-(cgfloat) weight//weight getter method implementation

{

return _weight;

}

Suggested writing format : can be used setter and getter method written in a piece of the way

/*

-(void) SetName: (NSString *) name

{

_name = name;

}

-(NSString *) name

{

return self;

}

*/

@end

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In the main function, import the Person.h file, create an object of the person class, and assign a value to the object, and take the value "on the code" who Dare to code!

#import <Foundation/Foundation.h>

#import "Person.h"

int main (int argc, const char * argv[])

{

Create an object for a person

Person *per = [[person alloc] init];

Assign a name to the person's object per

[Per setName:@ "Henry"];

Assigning a gender to an object per

[Per setsex:@ "male"];

Assign age to object per

[Per setage: +];

Assigning a weight to an object per

[Per setweight:];

NSLog (@ "per" name is:%@ ", per); At this point print per is just an address to print, to give the per object a specified printed instance.

If this is the case, the print result is: the name of per is:<person:0x100201e10>

NSLog (@ "per" name :%@ sex :%@ Age :%ld weight :%.2f ", [per Name],[per sex],[per age], [per weight]);

Print Result: per name: Henry Sex: Male Age: Weight: 160.00

re-assigning a value to Object per

[Per setName:@ "Lily" sex:@ "female" Age: weight: +];

NSLog (@ "per" name :%@ sex :%@ Age :%ld weight :%.2f ", [per Name],[per sex],[ per age],[per weight]);

printing results: per name: Lily Sex: Female Age: Weight: 96.00

Per to invoke the method of the person class

[per sayhi];

return 0;

}

OK, OC The second course is finished, I do not know if anyone will read my blog, if you see these friends, can give some advice, because I am also a beginner, we inspire each other.

Today's time is early, I am going to learn the next chapter of the content

IOS 2 Setter and getter