Applying a currency symbol based on a tested string value

Question

My conditional code here seems repetitive and long. Is there a better approach? I want to test for a string value in a NSDictionary object and then depending upon the value prefix a UILabel with $, £, ¥ currency symbols.

I've just shown 2 examples below. I have more currencies and the code is very long.

if ([[item objectForKey:@"currency"] isEqualToString:@"EUR"]) {

    NSString *priceConvertToStr = [NSString stringWithFormat:@"€%@", [[item objectForKey:@"price"]stringValue]];

    NSString *priceStringFix = [priceConvertToStr
                                stringByReplacingOccurrencesOfString:@"(null)" withString:@""];

    priceLabelText.text = priceStringFix;
    [imgView2 addSubview:priceLabelText];

}

if ([[item objectForKey:@"currency"] isEqualToString:@"GBP"]) {
    NSString *priceConvertToStr = [NSString stringWithFormat:@"€%@", [[item objectForKey:@"price"]stringValue]];

    NSString *priceStringFix = [priceConvertToStr
                                stringByReplacingOccurrencesOfString:@"(null)" withString:@""];

    priceLabelText.text = priceStringFix;
    [imgView2 addSubview:priceLabelText];

}
if ([[item objectForKey:@"currency"] isEqualToString:@"USD"]) {
    NSString *priceConvertToStr = [NSString stringWithFormat:@"$%@", [[item objectForKey:@"price"]stringValue]];

    NSString *priceStringFix = [priceConvertToStr
                                stringByReplacingOccurrencesOfString:@"(null)" withString:@""];

    priceLabelText.text = priceStringFix;
    [imgView2 addSubview:priceLabelText];

}

Answer 1

I'd create an NSDictionary holding those prefixes and wrap that whole thing into its own method, like so:

-(NSString *) prefixForCurrency:(NSString *)currency{
    NSDictionary *currencyPrefixes = @{@"EUR": @"€", @"USD" : @"$", @"GBP" : @"£", @"NOK" : @"kr." };
    NSString *returnString = [currencyPrefixes objectForKey:currency];  

    return returnString;
}

Then, instead of your current mass of if-statements you'd have something like the following:

NSString *currency = [item objectForKey:@"currency"];
NSString *currencyPrefix = [self prefixForCurrency: currency];

NSString *price = [item objectForKey:@"price"];
NSString *priceString = [NSString stringWithFormat:@"%@ %@", currencyPrefix, price];

In case you were wondering: the main reason I wrap the prefixDictionary in its own method is in case you'd for instance prefer to fetch this list from a file later on. Then you can just alter the innards of that one method...