Preg_match_all for global matching in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find all matches of 'cat' in the string.

PHP

<?php
$subject = "The cat sat on the cat mat.";
preg_match_all([1], $subject, $matches);
print_r($matches[0]);
?>

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

A"/cat/i"

B"cat"

C"/cat/"

D"/cat/g"

Attempts:

3 left

💡 Hint

Common Mistakes

Using the pattern without slashes causes an error.

Adding 'g' modifier is invalid in PHP regex.

The pattern must be enclosed in slashes to be a valid regex in PHP. So "/cat/" is correct.

2fill in blank

medium

Complete the code to perform a case-insensitive global match for 'dog'.

PHP

<?php
$subject = "Dog dog DOG doG";
preg_match_all([1], $subject, $matches);
print_r($matches[0]);
?>

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

A"/dog/i"

B"/dog/"

C"dog"

D"/dog/g"

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'g' modifier which is invalid in PHP.

Not using slashes around the pattern.

The 'i' modifier makes the match case-insensitive. PHP does global matching by default with preg_match_all.

3fill in blank

hard

Fix the error in the code to correctly find all numbers in the string.

PHP

<?php
$subject = "123 abc 456 def 789";
preg_match_all([1], $subject, $matches);
print_r($matches[0]);
?>

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

A"/\d+/"

B"/d+/"

C"/\d*/"

D"/\D+/"

Attempts:

3 left

💡 Hint

Common Mistakes

Not escaping the backslash causes an error.

Using '\D' matches non-digits, which is wrong.

The pattern "/\d+/" matches one or more digits. The backslash must be escaped in PHP strings.

4fill in blank

hard

Fill both blanks to find all words starting with 'a' or 'A' in the string.

PHP

<?php
$subject = "Apple and apricot are awesome.";
preg_match_all([1], $subject, $matches, [2]);
print_r($matches[0]);
?>

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

A"/\b[aA]\w*/"

BPREG_OFFSET_CAPTURE

CPREG_PATTERN_ORDER

DPREG_SET_ORDER

Attempts:

3 left

💡 Hint

Common Mistakes

Using PREG_SET_ORDER changes the structure of matches.

Not escaping backslashes in the pattern.

The pattern matches words starting with 'a' or 'A'. PREG_PATTERN_ORDER organizes matches by pattern order.

5fill in blank

hard

Fill all three blanks to extract all email addresses from the text.

PHP

<?php
$text = "Contact us at [e-mail] or [e-mail].";
preg_match_all([1], $text, $matches, [2], [3]);
print_r($matches[0]);
?>

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

A"/[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/"

B0

CPREG_PATTERN_ORDER

DPREG_OFFSET_CAPTURE

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong offset or flags changes output structure.

Incorrect regex pattern misses valid emails.

The regex matches emails. Offset 0 means start at beginning. PREG_PATTERN_ORDER organizes matches by pattern.