Question

Consider the following code

NSString *param_string @"1:3:6:10:15:22:28:30";
NSArray *params = [param_string componentsSeparatedByString:@":"];

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterNoStyle];

NSMutableArray *convertedArray = [[NSMutableArray alloc] initWithCapacity:[params count]];

for(int i = 0; i < [params count]; i++){
    [convertedArray insertObject:[formatter numberFromString:[params objectAtIndex:i] atIndex:i]];
}

Is there a better, more efficient way of achieving this? The initial param_string could be longer in practice but I don’t expect there to ever be more than approximately 200 elements in the params array.

Thanks

Answer 1

How about this.

Add a category to NSString

@interface NSString(MyConverter)

-(NSDecimalNumber*) decimalNumberValue;

@end

@implementation NSString(MyConverter)

-(NSDecimalNumber*) decimalNumberValue
{
    return [NSDecimalNumber decimalNumberWithString: self];
}

@end

Now you can do this

NSString *param_string @"1:3:6:10:15:22:28:30";
NSArray *params = [param_string componentsSeparatedByString:@":"];

NSArray* decimalNumbers = [params valueForKey: @"decimalNumberValue"];

Clearly if you want some other object than a NSDecimalNumber, just alter your category accordingly. The method just has to return an object that can be put in an array.