L7 Flashcards
What is an array in C#?
An array is a collection of variables (elements) of the same type, identified by an index starting at 0.
How do you declare and initialize a one-dimensional array in C#?
int[] myArray = { 1, 2, 3, 4, 5 };
What is the default value of array elements in C#?
Array elements are initialized to their default values (e.g., 0 for integers, null for strings, false for booleans).
How do you create an array with a fixed length?
int[] myArray = new int[6]; // Creates an array with 6 elements initialized to 0.
How can you access or modify an element in an array?
Use the element’s index:
myArray[0] = 10; // Assigns 10 to the first element.
int firstElement = myArray[0]; // Accesses the first element.
What happens if you try to access an array index out of bounds?
An IndexOutOfRangeException is thrown.
What is the purpose of the foreach loop with arrays?
The foreach loop iterates through each element of an array.
foreach (int number in myArray) {
Console.WriteLine(number);
}
How do you iterate through an array using a for loop?
for (int i = 0; i < myArray.Length; i++) {
Console.WriteLine(myArray[i]);
}
How do you create and initialize a multidimensional array in C#?
int[,] matrix = {
{1, 2, 3},
{4, 5, 6}
};
How do you access elements in a two-dimensional array?
Use two indices:
int value = matrix[1, 2]; // Accesses row 1, column 2.
What is the difference between a one-dimensional and two-dimensional array?
One-dimensional array: Linear structure (e.g., int[]).
Two-dimensional array: Grid-like structure with rows and columns (e.g., int[,] ).
How do you read input into an array from the console?
int n = int.Parse(Console.ReadLine());
int[] array = new int[n];
for (int i = 0; i < n; i++) {
array[i] = int.Parse(Console.ReadLine());
}
How do you print an array to the console?
foreach (int value in array) {
Console.WriteLine(value);
}
What is the purpose of the Length property in arrays?
The Length property returns the total number of elements in an array.
How do you declare an array of strings in C#?
string[] daysOfWeek = { “Monday”, “Tuesday”, “Wednesday” };
What are zero-based arrays?
Arrays in C# are zero-based, meaning the first element has an index of 0 and the last element has an index of Length - 1.
How do you create a dynamic array in C#?
Use a collection like List<T> instead of an array.</T>
How should you use arrays effectively in exams or projects?
- Know the syntax for declaring, initializing, and iterating arrays.
- Be careful with index boundaries to avoid exceptions.
- Use foreach for readability and for for flexibility.
What is the best way to handle multidimensional arrays?
Always visualize rows and columns when working with two-dimensional arrays. Label indices for clarity in nested loops.
How do you choose between arrays and collections?
Use arrays for fixed sizes and collections (e.g., List<T>) for dynamic resizing.</T>
