URL, Array, and string-input demonstrations for CS132

demo_Array.m

/**
 @brief Demonstrate getting textual user input and adding it to an array, plus displaying array contents.
 */
void demo_Array(void);

void demo_Array(void)
{
    //An array of "to do" items, which can be altered
    NSMutableArray* todoList = nil;
    
    //Pointing todoList at an allocated, initialized Mutable Array instance
    todoList = [[NSMutableArray alloc] init];
    
    //A string to keep track of a single to-do item
    NSString* todoItem = nil;
    
    //A C-style string for storing user input text
    char userInput[100];
    
    //Loop five times to get user inputs
    for(int i=0; i<5; i++)
    {
        //Prompt (CS131 style)
        printf("Enter todo item %d: ", i);
        
        //Scan input (CS131 style)
        scanf("%99s", userInput);
        
        //Convert C-string (array of characters) to NSString (String object)
        todoItem = [[NSString alloc] initWithCString:userInput
                                            encoding:NSASCIIStringEncoding];
        
        //Mutate the list by adding an item to it
        [todoList addObject:todoItem];
    }
    
    //Mutate the list by changing its order
    [todoList sortUsingSelector: @selector(localizedCaseInsensitiveCompare:)];
    
    //Loop over every item in the list and display it
    for(NSString* item in todoList)
    {
        NSLog(@"You should do: %@", item);
    }
}

demo_URL.m

/**
 @brief Demonstrate constructing a URL from strings and fetching HTML at the targeted location.
 */
void demo_URL(void);

void demo_URL(void)
{
    //A string, like you'd type to go to a server
    NSString* webserverAddress = @"http://henry.wells.edu/";
    //A URL (Uniform Resource Location) object based on that string
    NSURL* webserverURL = [NSURL URLWithString:webserverAddress];
    
    //A string, like you'd type to finish off a web address
    NSString* pbkInitiativesAddress = @"~pbk/index.html#Initiatives";
    //A URL, based on a relative path and another, base, URL
    NSURL* pbkURL = [NSURL URLWithString:pbkInitiativesAddress
                           relativeToURL:webserverURL];
    
    //The content you get by loading that URL
    NSString* contents = [NSString stringWithContentsOfURL:pbkURL
                                              usedEncoding:NULL
                                                     error:NULL];
    
    //Display one particular string version of the URL, as well as the contents it indicated
    NSLog(@"Contents of %@: \n\n%@", [pbkURL absoluteString], contents);
}