如何从Twitter API解析月份和年份返回JSON

Question

Suppose Twitter returns Wed Sep 14 18:52:57 +0000 2011 in JSON format. How do i go about parsing it so that the display looks something like Sep 2011 . Im aware of DateFormatter . I tried the following code but it keeps returning me Null .

NSString *created = [(NSDictionary *)TWData objectForKey:@"created_at"];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"MMM yyyy"];
    NSDate *date = [dateFormatter dateFromString:created];
   tweetingSince.text= [NSString stringWithFormat:@"@%@",[dateFormatter    stringFromDate:date]];

Answer 1

You are using same date format to parse the input string created to NSDate and to create final output format from the parsed date. Date formatter is unable to parse date Wed Sep 14 18:52:57 +0000 2011 using date format MMM yyyy . This is why the date is nil.

Edit: Also quick googling gave me this result on SO: iPhone + Twitter API: Converting time?

Edit 2: Your code with proper NSDate parsing would look like this

NSString *created = [(NSDictionary *)TWData objectForKey:@"created_at"];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"]];
//  Parse input string to NSDate
[dateFormatter setDateFormat:@"EEE MMM dd HH:mm:ss Z yyyy"];
NSDate *date = [dateFormatter dateFromString:created];
//  Convert parsed date to output format
[dateFormatter setDateFormat:@"MMM yyyy"];
tweetingSince.text= [NSString stringWithFormat:@"@%@",[dateFormatter    stringFromDate:date]];

Answer 2

You can do it like this

NSString *myString = @"Wed Sep 14 18:52:57 +0000 2011";

    NSCharacterSet *delimiters = [NSCharacterSet characterSetWithCharactersInString:@" "];
    NSArray *components = [myString componentsSeparatedByCharactersInSet:delimiters];

    NSLog(@"dilip-%@",components);

Output will be

dilip-(
    Wed,
    Sep,
    14,
    "18:52:57",
    "+0000",
    2011
)

Now you can select any value from array and create new string using that value.

NSString * firstStr = [components objectAtIndex:1];
NSString * secondStr = [components objectAtIndex:5];


NSString * fullStr = [NSString stringWithFormat:@"%@ %@",firstStr,secondStr];

NSLog(@"dilip - %@",fullStr);

Output will be

dilip - Sep 2011