Why array functions matter in PHP - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get the number of elements in the array.

PHP

<?php
$fruits = ['apple', 'banana', 'cherry'];
$count = [1]($fruits);
echo $count;
?>

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

Acount

Bstrlen

Csizeof

Darray_length

Attempts:

3 left

💡 Hint

Common Mistakes

Using strlen() which counts string length, not array elements.

Using array_length which is not a PHP function.

The count() function returns the number of elements in an array.

2fill in blank

medium

Complete the code to add a new element 'orange' to the end of the array.

PHP

<?php
$fruits = ['apple', 'banana'];
array_[1]($fruits, 'orange');
print_r($fruits);
?>

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Ashift

Bpop

Cpush

Dunshift

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_pop() which removes the last element.

Using array_shift() which removes the first element.

The array_push() function adds one or more elements to the end of an array.

3fill in blank

hard

Fix the error in the code to check if 'banana' is in the array.

PHP

<?php
$fruits = ['apple', 'banana', 'cherry'];
if ([1]('banana', $fruits)) {
    echo 'Found banana';
} else {
    echo 'Banana not found';
}
?>

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

Aarray_key_exists

Bin_array

Carray_search

Disset

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_key_exists which checks keys, not values.

Using isset which checks if a variable is set.

The in_array() function checks if a value exists in an array and returns true or false.

4fill in blank

hard

Fill both blanks to create an array of squares for numbers 1 to 5.

PHP

<?php
$numbers = [1, 2, 3, 4, 5];
$squares = array_map(function([1]) {
    return [2] * [1];
}, $numbers);
print_r($squares);
?>

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A$n

C$num

D$number

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inside and outside the function argument.

Forgetting to multiply the variable by itself.

The anonymous function takes each number as $n and returns its square by multiplying $n * $n.

5fill in blank

hard

Fill all three blanks to filter numbers greater than 3 and create a new array with those numbers doubled.

PHP

<?php
$nums = [1, 2, 3, 4, 5];
$filtered = array_filter($nums, function([1]) {
    return [2] > 3;
});
$doubled = array_map(function([3]) {
    return [3] * 2;
}, $filtered);
print_r($doubled);
?>

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

A$num

C$n

D$val

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently inside the functions.

Not returning the correct condition in the filter function.

The filter function uses $num to check if the number is greater than 3. The map function uses $n to double each filtered number.