NSURLConnectionDelegate - Use of undefined identifier 'connection'

Question

I'am new to objective-c so please for forbearance. I just copied and pasted code from tutorial about post request in ios and during implementing connection method i've got an following error: ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController <NSURLConnectionDelegate>

@property (weak, nonatomic) IBOutlet UITextField *userNameTextField;
@property (weak, nonatomic) IBOutlet UITextField *passwordTextField;

- (IBAction)postRequest:(id)sender;

@end

ViewController.m

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)postRequest:(id)sender {

    NSString *post = [NSString stringWithFormat:@"Username=%@&Password=%@",@"randomUser",@"randomPassword"];
    NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
    NSString *postLength = [NSString stringWithFormat:@"%lu", [postData length]];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:[NSString stringWithFormat:@"http:/example.com/users/show.json"]]];
    [request setHTTPMethod:@"POST"];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];
    NSURLConnection * conn = [[NSURLConnection alloc]initWithRequest:request delegate:self];

    if(conn) {
        NSLog(@"Connection Successful");
    } else {
        NSLog(@"Connection could not be made");
    }

    - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
        _responseData = [[NSMutableData alloc] init];
    }


    - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
        [_responseData appendData:data];
    }

    - (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse*)cachedResponse {
        return nil;
    }

    - (void)connectionDidFinishLoading:(NSURLConnection *)connection {
        NSString* respsoneString = [NSString stringWithUTF8String:[_responseData bytes]];
    }

    - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
        //Do something if there is an error in the connection
    }


}
@end

Answer 1

did received Response is a NSURLConnectionDataDelegate method include that photo call in your code

@interface ViewController : UIViewController <NSURLConnectionDelegate, NSURLConnectionDataDelegate>

in your code you didn't closed the } body of method above it