Question

I have created a quiz which draws questions from a plist into an array and displays the question in a uilabel and the three possible answers in uibuttons. My question is how can I create a random order for the buttons so that the three answers don’t always show up in the same order?

Any help would be most appreciated.

Jamie

Answer 1

Going along with @Abizern’s answer. It would be more efficient to have the fixed buttons and randomise the array. You could do something like this:

//NSMutableArray *questions = [[NSMutableArray alloc] initWithObjects:@"1", @"2", @"3", @"4", nil];

NSMutableArray *unorderedQuestions = [[NSMutableArray alloc] init];
for (int i=0; i < [questions count]; i++) {
    int lowerBound = 0;
    int upperBound = 100;
    int rndValue = lowerBound + arc4random() % (upperBound - lowerBound);
    [unorderedQuestions addObject:[[NSArray alloc] initWithObjects:[questions objectAtIndex:i], [NSString stringWithFormat:@"%i", rndValue], nil]];
}

NSArray* sortedArray = [unorderedQuestions sortedArrayUsingFunction:order context:NULL];
//or
// questions = [unorderedQuestions sortedArrayUsingFunction:order context:NULL];
NSLog(@"%@", sortedArray);

and put this function somewhere:

static NSInteger order (id a, id b, void* context) {
    NSString* catA = [a lastObject];
    NSString* catB = [b lastObject];
    return [catA caseInsensitiveCompare:catB];
}

This basically assigns a random number (between 0 and 100) to each question and sorts it by that number. You can then just make sortedArray global (or possibly just overwrite your questions array) and display objects sequentially and they will be shuffled.

[btnA setTitle:[[[questions objectAtIndex:r] objectAtIndex:0] objectForKey:@"A"] forState:UIControlStateNormal];

Judging by your code, you may need to amend a few lines: (but you could also create a currentQuestionsArray and assign it to [questions objectAtIndex:r] before the code above)

for (int i=0; i < [questions count]; i++) {
//to
for (int i=0; i < [[questions objectAtIndex:r] count]; i++) {`

and

[unorderedQuestions addObject:[[NSArray alloc] initWithObjects:[questions objectAtIndex:i], [NSString stringWithFormat:@"%i", rndValue], nil]];
//to
[unorderedQuestions addObject:[[NSArray alloc] initWithObjects:[[questions objectAtIndex:r] objectAtIndex:i], [NSString stringWithFormat:@"%i", rndValue], nil]];`

I think this is the most robust solution, as in the future you may have a different number of answers for a particular question and would not need to edit this to do so!