Adding questions
- Java course
- Intermediate
- Lesson 43/116
- 6 min
Add questions with addQuestion.
Adding questions
The second lesson defines the Quiz class. The quiz holds questions in an array. An add method adds new questions; a count field tracks how many questions exist.
Example: class Quiz { Question[] questions; int count; Quiz() { questions = new Question[10]; count = 0; } void add(Question q) { questions[count] = q; count++; } }. Here the questions array has a capacity of 10. The add method adds one question each call and increments count. This structure stores questions in order. To avoid exceeding array bounds, count is checked; we keep it simple for now.
Storing questions in an array
The Quiz class stores questions in a Question[] array. An array is a fixed-size data structure; its capacity is specified when created. The add method places the question at the next empty slot.
Example: questions = new Question[10]; creates an array of 10 elements. questions[0] holds the first question, questions[1] the second. The count variable indicates the next empty index. When add is called, questions[count] = q; adds the question and count is incremented. This is a simple but effective storage method. When the array is full, no more additions are made; we do not hit this limit for now.
Practice Add the Quiz class
Add a Quiz class to the file. Write Question[] questions and int count fields. In the Quiz() constructor create the array with new Question[10], set count = 0. Add a void add(Question q) method; run questions[count] = q; and count++. Put main inside Quiz; create a Quiz instance, add two questions and print count.
Starter code
class Question {
String text;
String answer;
Question(String t, String a) {
text = t;
answer = a;
}
public String toString() {
return text + " = " + answer;
}
}
// Add the Quiz class
// questions array, count, constructor and add method
// Instantiate and print in mainSample solution
class Question {
String text;
String answer;
Question(String t, String a) {
text = t;
answer = a;
}
public String toString() {
return text + " = " + answer;
}
}
class Quiz {
Question[] questions;
int count;
Quiz() {
questions = new Question[10];
count = 0;
}
void add(Question q) {
questions[count] = q;
count++;
}
public static void main(String[] args) {
Quiz quiz = new Quiz();
quiz.add(new Question("Capital", "Paris"));
quiz.add(new Question("City", "London"));
System.out.println(quiz.count);
}
}Expected output
2
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match the Quiz parts
| Term | Meaning |
|---|---|
Question[] questions |
Question array |
int count |
Question count |
void add(Question q) |
Add method |
count++ |
Increment counter |
2 What does the count field track in the Quiz class?
- The score
- The array size
- The quiz duration
- The question count Correct answer
Explanation: The question count — count holds how many questions are added.
3 Complete the add method
void add(Question q) {
questions[count] = q;
____;
}void add(Question q) {
questions[count] = q;
count++;
}Explanation: count is incremented on each addition.