Possible to use variables and/or parameters with NSLocalizedString?

If what you want is to return the localized version of "This is an Apple/Orange/whatever", you'd want:

NSString *localizedVersion = NSLocalizedString(([NSString stringWithFormat:@"This is an %@", @"Apple"]), nil);

(I.e., the nesting of NSLocalizedString() and [NSString stringWithFormat:] are reversed.)

If what you want is the format to be localized, but not the substituted-in value, do this:

NSString *finalString = [NSString stringWithFormat:NSLocalizedString(@"SomeFormat", nil), @"Apple"];

And in your Localizable.strings:

SomeFormat = "This is an %@";

I just want to add one very helpful definition which I use in many of my projects.

Inspired by androids possibility, I've added this function to my header prefix file:

#define NSLocalizedFormatString(fmt, ...) [NSString stringWithFormat:NSLocalizedString(fmt, nil), __VA_ARGS__]

This allows you to define a localized string like the following:

 "ExampleScreenAuthorizationDescriptionLbl"= "I authorize the payment of %@ to %@.";

and it can be used via:

self.labelAuthorizationText.text = NSLocalizedFormatString(@"ExampleScreenAuthorizationDescriptionLbl", self.formattedAmount, self.companyQualifier);

For swift :

let myString = String(format: NSLocalizedString("I authorize the payment of %d ", comment: ""), amount)