Question

Okay I’ve been trying at this for about 2-3 hours now and I don’t seem to quite get it. Here is the code and a brief explanation:
I’m trying to make two lists of words, pull one word from each of those lists at random, and display both words (along with a third) on the screen when a button is pressed. Here is the code:

   #import "Project001ViewController.h"

    @implementation Project001ViewController

    -(ArrayOfWords *) advs
    {
        if(!advs){
            advs = [[ArrayOfWords alloc] init];
            NSString* advpath = @"/WordLists/adverbs.txt";
            NSLog(@"1");
            [[self advs] populateListOfWords:advpath];
        }
        return advs;
    }


    -(ArrayOfWords *) adjs
    {
        if (!adjs) {
            adjs = [[ArrayOfWords alloc] init];
            NSString* adjpath = @"/WordLists/adjectives.txt";
            [[self adjs] populateListOfWords:adjpath];
            NSLog(@"2");
        }
        return adjs;
    }


    - (IBAction)generate:(UIButton *)sender;
    {
        //int randy = arc4random() % 11;
        //NSNumber* num= [NSNumber numberWithInteger:randy];


        NSString* obj = @"app";
        NSString* adverb = [[self advs] randomItem];
        NSString* adjective = [[self adjs] randomItem];
        NSLog(@"%i   %i",[adjs size],[advs size]);



        NSLog(@"1 %@ %@ %@.",adverb, adjective, obj);
        //NSLog(@"%@",thePhrase);
        [display setText:@"Hi"];
    }


    @end

I’m having trouble on the last NSLog line:

 NSString* obj = @"app";
        NSString* adverb = [[self advs] randomItem];
        NSString* adjective = [[self adjs] randomItem];
        NSLog(@"%i   %i",[adjs size],[advs size]);
        NSLog(@"1 %@ %@ %@.",adverb, adjective, obj);

Instead of getting the two randomly selected words (using arc4random() to produce them) the array returns Null. But I know FOR CERTAIN. That the array’s are not empty because the NSLog Line where I print [adjs size] and [advs size] I get the correct sizes of the list of words. I just want to know what is causing them to print Null here.

populateListOfWords, randomItem, and size methods:

- (NSArray *) populateListOfWords:(NSString *) path {

    //gets the components of the file into an NSString
    NSString *wordListString = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    //returns an array of all the words (uses the next line indicator '\n' to know when it's at the end of the word
    NSArray* words = [wordListString componentsSeparatedByString:@"\n"];

    length=(NSNumber*)([words count]);
    return words;

  }


-(NSString*) randomItem{
    //returns random object in list
    return (NSString*)[list objectAtIndex:(arc4random() % (int)length)] ;

}

-(int) size{
    //returns size of list
    return (int)length;
}

(If more code is needed let me know and thank you in advanced for any and all help).

Answer 1

This method is the problem:

- (NSArray *) populateListOfWords:(NSString *) path {

    //gets the components of the file into an NSString
    NSString *wordListString = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    //returns an array of all the words (uses the next line indicator '\n' to know when it's at the end of the word
    NSArray* words = [wordListString componentsSeparatedByString:@"\n"];

    length=(NSNumber*)([words count]);
    return words;

  }

It wasn’t actually putting the words in a list that anyone else could access. I had to just modify it like so:

- (void) populateListOfWords:(NSString *) path {

    //gets the components of the file into an NSString
    NSString *wordListString = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    //returns an array of all the words (uses the next line indicator '\n' to know when it's at the end of the word
    NSArray* words = [wordListString componentsSeparatedByString:@"\n"];

    list = words;
    length=(int)([words count]);
  }

Now it gives me the correct output. But for some reason when I press the button twice it crashes. Oh well that’s a new problem. Thanks again for all the help.

UPDATE
Turns out advs and adjs were being released so the second go around it was trying to access a nil value because when I call [self advs] [self adjs] the pointers exist, but their contents do not. I had to go back and refill them each time basically removing the if (!advs) and if (adjs) parts. It now works as intended.