Xcode object-c 常用轉換

NSMutableArray → NSArray

    NSArray *array = [NSArray arrayWithArray:mutableArray]; //array is empty

    NSArray *array = [mutableArray copy]; //array is nil

NSDate↔ NSString

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

    [f setDateFormat:@"yyyy-MM-dd"];

    NSString *strDate = [f stringFromDate:[NSDate date]];

    NSDate *date = [f dateFromString:@"2015-10-04"];

NSNumber↔int

    int i=10;

    

    NSNumber *inumber=[NSNumber numberWithInt:i];

    

    i=[inumber intValue];

UUID/GUID→ NSString

 NSString *UUID=[[NSUUID UUID] UUIDString];

int↔NSString

  int value=0;

  NSString *str=[@(value) stringValue];

  value =[str intValue];