convert NSArray of NSString(s) to NSArray of NSMutableString(s)

Question

How to do that without having to \"scroll\" the entire given array with a \"for\" loop?

Answer 1

I wrote a dictionary method on NSArray to be able to write cleaner functional code

-(NSArray *)arrayByPerformingBlock:(id (^)(id))performBlock 
{
    NSMutableArray *array = [NSMutableArray array];
    for (id element in self)
         [array addObject:performBlock(element)];
    return [NSArray arrayWithArray:array];
}

usage:

arrayWithStrings = [arrayWithStrings arrayByPerformingBlock:^id(id element) {return [[element mutableCopy] autorelease];}];

This was inspired by list comprehensions I know from Python. I also wrote versions of this methods with testing. See my arraytools.