Array unique and flip in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to remove duplicate values from the array.

PHP

<?php
$numbers = [1, 2, 2, 3, 4, 4, 5];
$unique = [1]($numbers);
print_r($unique);
?>

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

Aarray_unique

Barray_flip

Carray_merge

Darray_map

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_flip instead of array_unique.

Trying to use array_merge which combines arrays.

Using array_map which applies a callback to elements.

The array_unique function removes duplicate values from an array.

2fill in blank

medium

Complete the code to flip keys and values of the array.

PHP

<?php
$colors = ['red', 'green', 'blue'];
$flipped = [1]($colors);
print_r($flipped);
?>

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

Aarray_reverse

Barray_unique

Carray_flip

Darray_keys

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_unique which removes duplicates.

Using array_reverse which reverses order but not keys and values.

Using array_keys which returns keys only.

The array_flip function swaps the keys and values of an array.

3fill in blank

hard

Fix the error in the code to correctly remove duplicates and flip the array.

PHP

<?php
$items = ['a', 'b', 'a', 'c'];
$unique = [1]($items);
$flipped = array_flip($unique);
print_r($flipped);
?>

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

Aarray_flip

Barray_unique

Carray_merge

Darray_map

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_flip first which does not remove duplicates.

Using array_merge which combines arrays incorrectly.

Using array_map which is not for removing duplicates.

First remove duplicates with array_unique, then flip keys and values.

4fill in blank

hard

Fill both blanks to create an array of unique values and then flip keys and values.

PHP

<?php
$fruits = ['apple', 'banana', 'apple', 'orange'];
$unique = [1]($fruits);
$flipped = [2]($unique);
print_r($flipped);
?>

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

Aarray_unique

Barray_flip

Carray_merge

Darray_reverse

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_merge instead of array_unique.

Using array_reverse instead of array_flip.

Flipping before removing duplicates.

Use array_unique to remove duplicates, then array_flip to swap keys and values.

5fill in blank

hard

Fill all three blanks to remove duplicates, flip the array, and then get the keys of the flipped array.

PHP

<?php
$letters = ['x', 'y', 'x', 'z'];
$unique = [1]($letters);
$flipped = [2]($unique);
$keys = [3]($flipped);
print_r($keys);
?>

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

Aarray_unique

Barray_flip

Carray_keys

Darray_values

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_values instead of array_keys.

Flipping before removing duplicates.

Skipping the step to get keys.

First remove duplicates with array_unique, then flip keys and values with array_flip, and finally get the keys with array_keys.