Adding questions
Learn to add questions with the AddQuestion method.
Quiz class and adding questions
In this lesson we define the Quiz class. It will hold a List<Question> of questions and an AddQuestion method to add new questions. A Count method will report how many questions there are.
List<Question> is a dynamically growing collection. Use questions.Add(q) to add a new question. The questions.Count property gives the list length. AddQuestion takes a Question from outside and adds it to the list.
Using List<Question>
List<Question> is one of C#'s generic collections. The line using System.Collections.Generic; must be at the top of the file. Declaration: private List<Question> questions = new List<Question>();.
The list starts empty. Use questions.Add(q) to append an element. The questions.Count property gives the length. The list grows its capacity automatically as needed; you don't have to set a size in advance.
Exercise Add a question and count
Add a private List<Question> questions = new List<Question>(); field, a public void AddQuestion(Question q) method and a public int Count() method to Quiz. In Main, create a Quiz, add one question and print Count.
Show example solution
Write the Quiz class as `class Quiz { private List<Question> questions = new List<Question>(); public void AddQuestion(Question q) { questions.Add(q); } public int Count() { return questions.Count; } }`. In Main write `var quiz = new Quiz(); quiz.AddQuestion(new Question { Text = "Capital?", Answer = "Ankara" }); Console.WriteLine(quiz.Count());`.
Example solution:
using System;
using System.Collections.Generic;
class Question
{
public string Text;
public string Answer;
}
class Quiz
{
private List<Question> questions = new List<Question>();
public void AddQuestion(Question q)
{
questions.Add(q);
}
public int Count()
{
return questions.Count;
}
}
class Program
{
static void Main()
{
var quiz = new Quiz();
quiz.AddQuestion(new Question { Text = "Capital?", Answer = "Ankara" });
Console.WriteLine(quiz.Count());
}
}Test yourself
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Fill in the blank: AddQuestion signature
class Quiz { public void AddQuestion(____) { questions.Add(q); } }Show answer
class Quiz { public void AddQuestion(Question q) { questions.Add(q); } } -
Which is suitable for storing questions in the Quiz class?
- List<Question>
- string
- int
- Question
Show answer
List<Question> — Correct. `List<Question>` holds many questions dynamically.
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Match: Quiz parts
- List<Question>
- question list
- AddQuestion
- adds a question
- Count
- question count
- new Quiz
- creates a new quiz