Multidimensional arrays in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a 2D array with two rows.

PHP

<?php
$matrix = array(
    array(1, 2),
    [1]
);
print_r($matrix);
?>

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

Aarray(3, 4)

Barray(7, 8)

Carray(5, 6)

Darray(9, 10)

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single value instead of an array for the second row.

Forgetting to use the array() function for the second row.

The second row of the 2D array is created with array(5, 6).

2fill in blank

medium

Complete the code to access the element '8' from the 2D array.

PHP

<?php
$matrix = array(
    array(1, 2, 3),
    array(4, 5, 6),
    array(7, 8, 9)
);
echo $matrix[1];
?>

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

A[2][1]

B[1][2]

C[0][2]

D[2][2]

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up row and column indexes.

Using 1-based indexes instead of 0-based.

The element '8' is in the third row (index 2) and second column (index 1), so $matrix[2][1] accesses it.

3fill in blank

hard

Fix the error in the code to correctly add a new row to the multidimensional array.

PHP

<?php
$matrix = array(
    array(1, 2),
    array(3, 4)
);
$matrix[] = [1];
print_r($matrix);
?>

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

Aarray(5, 6)

B5, 6

C[5, 6]

D"5, 6"

Attempts:

3 left

💡 Hint

Common Mistakes

Adding values without wrapping them in array().

Using string instead of array for the new row.

To add a new row, you must add an array. So array(5, 6) is correct.

4fill in blank

hard

Fill both blanks to create a 3x3 matrix with all zeros.

PHP

<?php
$matrix = array(
    array([1], [2], 0),
    array(0, 0, 0),
    array(0, 0, 0)
);
print_r($matrix);
?>

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

A0

B1

Cnull

D"0"

Attempts:

3 left

💡 Hint

Common Mistakes

Using string "0" instead of integer 0.

Using 1 or null instead of 0.

To create a matrix with all zeros, use 0 for each element.

5fill in blank

hard

Fill all three blanks to create an associative multidimensional array representing students and their scores.

PHP

<?php
$students = array(
    "Alice" => array("Math" => [1], "Science" => [2]),
    "Bob" => array("Math" => [3], "Science" => 85)
);
print_r($students);
?>

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

A90

B80

C75

D95

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings instead of numbers for scores.

Mixing up scores between students or subjects.

Alice's Math score is 95, Science is 80, and Bob's Math score is 75.