Beginning Mac OS® X Programming

A.7. Chapter 7

A.7.1. Exercise 1 solution

After you have created the Discus project, replace the contents of the Discus.m file with the following code:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    // Store data in an array of dictionaries
    NSArray *discs =
        [NSArray arrayWithObjects:
            [NSDictionary dictionaryWithObjectsAndKeys:
                @"CD",                      @"Type",
                [NSNumber numberWithInt:3], @"LengthInMinutes",
                @"Lounge Room",             @"Location",
                @"BB Bonkas",               @"Artist",
                nil],
            [NSDictionary dictionaryWithObjectsAndKeys:
                @"CD",                      @"Type",
                [NSNumber numberWithInt:4], @"LengthInMinutes",
                @"Attic",                   @"Location",
                @"CC Charmers",             @"Artist",
                nil],
            [NSDictionary dictionaryWithObjectsAndKeys:
                @"DVD",                         @"Type",
                [NSNumber numberWithInt:121],   @"LengthInMinutes",

@"Attic", @"Location", @"TJ Slickflick", @"Lead Actor", @"LJ Slickflick", @"Director", nil], nil]; // Extract a few entries, and print them in the console NSLog(@"The third entry in the library is a %@", [[discs objectAtIndex:2] objectForKey:@"Type"]); NSLog(@"The director is %@", [[discs objectAtIndex:2] objectForKey:@"Director"]); // Write the array to file NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Desktop/discus.plist"]; [discs writeToFile:path atomically:YES]; // Read the array back from the file, and write it to the console NSArray *newDiscs = [[[NSArray alloc] initWithContentsOfFile:path] autorelease]; NSLog(@"The database contents are:\n%@", ...