Single-dimensional array declaration in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of array length after declaration

What is the output of this C# code snippet?

C Sharp (C#)

int[] numbers = new int[5];
Console.WriteLine(numbers.Length);

A 5

B 0

C 6

D Compilation error

💡 Hint

Remember that the Length property returns the number of elements in the array.

The array 'numbers' is declared with size 5, so its Length property returns 5.

❓ Predict Output

intermediate

Value of array element after declaration

What is the output of this C# code snippet?

C Sharp (C#)

int[] values = new int[3];
Console.WriteLine(values[1]);

A 1

B 0

C null

D IndexOutOfRangeException

💡 Hint

Default values for int elements in a new array are important here.

In C#, int arrays are initialized with default value 0 for each element.

❓ Predict Output

advanced

Output of array initialization with values

What is the output of this C# code snippet?

C Sharp (C#)

string[] fruits = new string[] {"apple", "banana", "cherry"};
Console.WriteLine(fruits[2]);

A apple

B banana

C cherry

D null

💡 Hint

Array indexing starts at zero.

The element at index 2 is "cherry" in the initialized array.

❓ Predict Output

advanced

Error type when accessing invalid index

What error does this C# code produce when run?

C Sharp (C#)

int[] arr = new int[2];
Console.WriteLine(arr[3]);

A No error, prints 0

B NullReferenceException

C ArgumentOutOfRangeException

D IndexOutOfRangeException

💡 Hint

Accessing an index outside the array bounds causes a runtime error.

Accessing index 3 in an array of size 2 throws IndexOutOfRangeException.

🧠 Conceptual

expert

Number of elements in a declared array

How many elements does the array contain after this declaration in C#?

double[] data = new double[10];

A 10

B 9

C 11

D 0

💡 Hint

The number inside the brackets specifies the array size.

The array 'data' is declared with size 10, so it contains 10 elements indexed 0 to 9.