字符串等于不工作的iOS

Following is my PHP code that sends response to a webservice request :

 $query = "select name,email,password from User where email='".$email."' AND password='".$password."'";
 $result = mysql_query($query);
 $num_rows = mysql_num_rows($result);


 if($num_rows==1)
 {
     sendResponse(200, json_encode("match"));
 }

 if($num_rows==0)
 {
     sendResponse(204, json_encode("not match"));
 }

Following is my iOS code:

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{   
    NSString *status = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@" Returned Json data : %@",status);


    if ([status isEqualToString:@"match"])
    {
        AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];

        [appDelegate OpenTabController];
    }

    //Boolean flag = [status isEqualToString:@"not match"];

    //NSLog(@"flag : %d",flag);

    if ([status isEqualToString:@"not match"])
    {
        NSLog(@"not match");


        UIAlertView *alertView = [[UIAlertView alloc]
                                      initWithTitle:@"Invalid email or password"
                                      message:@""
                                      delegate:nil
                                      cancelButtonTitle:@"OK"
                                      otherButtonTitles:nil];
        [alertView show];

    }
}

line [status isEqualToString:@"not match"] doesn't work.

Guys I have found the solution:

php code:

if($num_rows==1)
{
    $status = array(
    "status" => "match",
    );

    sendResponse(200, json_encode($status));
}

if($num_rows==0)
{
    $status = array(
    "status" => "not match",
    );

   sendResponse(204, json_encode($status));
}

iOS Code:

NSDictionary *result = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error: nil];

NSString *status = [result objectForKey:@"status"];
NSLog(@"Returned Json data : %@",status);

You can try debugging and check what the value in status is. I don't think there is any problem with string comparison in your code.

First You need to include the SBJson library to your project. Then import the json.h

#import "JSON.h"

Find the below code:

NSString *status = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSDictionary *dic = [status JSONValue];

This dictionary is your result.With this dictionary, you can check the value for your key.

PHP json_encode escaped space char. And it should make from 'not match' a json, like {'not match'}

First of all you are converting the string into a json repsonse. In your PHP code use the associative array to make a key value pair and then convert the data to JSON format in iOS using the JSON parser. Use objectForKey method on the converted dictionary

PHP Code

if($num_rows==1)
 {
$status = "match";
$status_array = array("status"=>"$status");
     sendResponse(200, json_encode($status_array));
 }

 if($num_rows==0)
 {
$status = "not match";
$status_array = array("status"=>"$status");
     sendResponse(204, json_encode($status_array));
 }

iOS Code Use the process below to parse json and accordingly get the value as required. http://www.raywenderlich.com/5492/working-with-json-in-ios-5