Substring extraction in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to extract the first 5 characters from the string.

PHP

<?php
$text = "Hello, world!";
$part = substr($text, 0, [1]);
echo $part;
?>

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

A5

B7

C12

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong length value.

Confusing start position with length.

The substr function extracts a part of the string starting at position 0 for 5 characters.

2fill in blank

medium

Complete the code to extract the substring starting from the 8th character to the end.

PHP

<?php
$text = "Hello, world!";
$part = substr($text, [1]);
echo $part;
?>

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

A7

B12

C0

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 6 instead of 7 as start position.

Forgetting that positions start at 0.

Starting at position 7 extracts the substring from the 8th character to the end.

3fill in blank

hard

Fix the error in the code to correctly extract 5 characters starting from the 3rd character.

PHP

<?php
$text = "Programming";
$part = substr($text, [1], 5);
echo $part;
?>

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

A0

B2

C5

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3 as start position which is actually the 4th character.

Confusing character count with position index.

Position 2 is the 3rd character because counting starts at 0.

4fill in blank

hard

Fill both blanks to extract the last 4 characters of the string.

PHP

<?php
$text = "Substring";
$part = substr($text, [1], [2]);
echo $part;
?>

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

A-4

B4

C3

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using positive start position which extracts from the beginning.

Using wrong length value.

Using a negative start position counts from the end. Length 4 extracts the last 4 characters.

5fill in blank

hard

Fill both blanks to filter for word lengths greater than 3.

PHP

<?php
$words = ["apple", "cat", "banana", "dog"];
$lengths = array_filter(array_map(function($word) {
    return strlen($word);
}, $words), function($len) {
    return $len [1] [2];
});
print_r($lengths);
?>

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

A>

B3

C<

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using less than or equal operators.

Confusing the comparison values.

The filter keeps lengths greater than 3.