---
title: "What is protocol in iOS"  
description: "What is protocol in iOS"  
author: "Anonymous User"  
published: 2015-02-26  
updated: 2015-02-27  
canonical: https://www.mindstick.com/forum/12985/what-is-protocol-in-ios  
category: "iphone"  
tags: ["iphone", "mobile development", "ios"]  
reading_time: 2 minutes  

---

# What is protocol in iOS

What is [protocol](https://www.mindstick.com/forum/55090/what-is-stateless-protocol) in [iOS](https://www.mindstick.com/articles/12222/core-data-and-how-to-use-it-in-ios-objective-c)?

## Replies

### Reply by Anonymous User

A protocol is a group of related properties and methods that can be implemented by any class.

Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation.

Lets understand this with the help of an example

```
// code of AddCountry.h file

#import <Foundation/Foundation.h> // Protocol Name
@protocol AddCountryProtocolDelegate <NSObject>
// protocol method that called after country added in list
@required
- (void) CountryAddedToList;
@end@interface AddCountry : NSObject
// hold country list.
@property (nonatomic, retain)NSMutableArray* CountryList;
// delegate object@property (nonatomic,strong) id
<AddCountryProtocolDelegate>delegate;
// method that add country to list-(void)addCountryToList:(NSString *)object;

@end
 

 /// Code of AddCountry.m file#import "AddCountry.h"
@implementation AddCountry-(void)addCountryToList:(NSString *)object{

    if(_CountryList==nil){

     _CountryList=[[NSMutableArray alloc]init];     }

    [_CountryList
addObject:object];

    [_delegate
CountryAddedToList];

}

@end
// code of view controller.h#import <UIKit/UIKit.h>#import "AddCountry.h"
@interface ViewController :
UIViewController<AddCountryProtocolDelegate>- (IBAction)AddCountryButtonTap:(id)sender;@property (strong, nonatomic) IBOutlet UITextField *TxtCountry;@property(strong,nonatomic)AddCountry *CountryObj;@end
// code of view controller.m- (void)viewDidLoad {    [super viewDidLoad];
// initialization of addcountry class  object and setting delegate._CountryObj=[[AddCountry alloc]init];

    _CountryObj.delegate=self;}
- (IBAction)AddCountryButtonTap:(id)sender {    [_CountryObj
addCountryToList:_TxtCountry.text];}
 #pragma mark  add country
class delegate method. this method is called after a country object added to
list.-(void)CountryAddedToList{    NSLog(@“Country
added to the list.");    _TxtCountry.text=nil;}
```


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Original Source: https://www.mindstick.com/forum/12985/what-is-protocol-in-ios

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