NSDate,NSString转化

NSDate to NSString

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

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

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

NSLog(@"%@", strDate);

[dateFormatter release];

NSString to NSDate

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

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

NSDate *date = [dateFormatter dateFromString:@"2010-08-04 16:01:03"];

NSLog(@"%@", date);

[dateFormatter release];

//String to number

NSNumberFormatter * f = [[NSNumberFormatter alloc] init]; 
[f setNumberStyle:NSNumberFormatterDecimalStyle]; 
NSNumber * myNumber = [f numberFromString:@"42"]; 
[f release];