OC NSData与NSString的互转

-(void)reverseDateToString{

NSDateFormatter *formatter = [[NSDateFormatter alloc]init];

[formatter setDateFormat:@"yyyy-MM-dd"];

NSDate *date = [[NSDate alloc]init];

NSString *dateStr = [formatter stringFromDate:date];

NSLog(@"date:---------%@",date);

NSLog(@"dateString:---------%@",dateStr);

}

-(void)reverseStringToDate{

NSString *dateStr = @"2016-12-02";

NSDateFormatter *dateformatter = [[NSDateFormatter alloc]init];

[dateformatter setDateFormat:@"yyyy-MM-dd"];

NSDate *date = [dateformatter dateFromString:dateStr];

NSLog(@"date:---------%@",date);

}