Multi-dimensional arrays in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a 2D array of integers with 3 rows and 4 columns.

C Sharp (C#)

int[,] matrix = new int[[1], 4];

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A3

B4

C5

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing rows and columns sizes.

Using a single-dimensional array syntax.

The first dimension is the number of rows, which is 3 here.

2fill in blank

medium

Complete the code to assign the value 10 to the element in the second row and third column of the 2D array.

C Sharp (C#)

matrix[[1], 2] = 10;

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A3

B1

C2

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 2 instead of 1 for the second row index.

Confusing row and column indices.

Array indices start at 0, so the second row is index 1.

3fill in blank

hard

Fix the error in the code to correctly declare and initialize a 2D array with 2 rows and 3 columns filled with zeros.

C Sharp (C#)

int[,] grid = new int[[1], 3];

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A2

B0

C3

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3 instead of 2 for the number of rows.

Using zero or one as the first dimension size.

The array should have 2 rows and 3 columns, so the first dimension is 2.

4fill in blank

hard

Fill both blanks to create a nested loop that prints all elements of a 2D array named 'data'.

C Sharp (C#)

for (int i = 0; i < data.GetLength([1]); i++) {
    for (int j = 0; j < data.GetLength([2]); j++) {
        Console.WriteLine(data[i, j]);
    }
}

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A0

B1

C2

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the dimension indices.

Using invalid dimension numbers like 2 or 3.

GetLength(0) returns the number of rows, GetLength(1) returns the number of columns.

5fill in blank

hard

Fill all three blanks to create a 2D array 'table' with 2 rows and 3 columns, assign 5 to the first element, and print it.

C Sharp (C#)

int[,] table = new int[[1], [2]];
table[0, 0] = [3];
Console.WriteLine(table[0, 0]);

Drag options to blanks, or click blank then click option'

A3

B5

C2

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping rows and columns in the declaration.

Assigning the wrong value to the first element.

The array has 2 rows and 3 columns, so dimensions are 2 and 3. The value 5 is assigned to the first element.