Preg_match for pattern matching in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the string contains the word 'cat'.

PHP

<?php
$string = "The cat is sleeping.";
if (preg_match([1], $string)) {
    echo "Found a cat!";
} else {
    echo "No cat found.";
}
?>

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

A"cat"

B"/dog/"

C"/cat/"

D"/Cat/"

Attempts:

3 left

💡 Hint

Common Mistakes

Using the pattern without slashes, like "cat" instead of "/cat/".

Using the wrong word in the pattern, like "/dog/".

The pattern must be enclosed in delimiters like slashes (/). So, "/cat/" is the correct pattern to find 'cat'.

2fill in blank

medium

Complete the code to check if the string starts with 'Hello'.

PHP

<?php
$string = "Hello world!";
if (preg_match([1], $string)) {
    echo "Starts with Hello.";
} else {
    echo "Does not start with Hello.";
}
?>

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

A"/world/"

B"/^Hello/"

C"/^world/"

D"/Hello$/"

Attempts:

3 left

💡 Hint

Common Mistakes

Using $ which matches the end of the string instead of ^.

Using a pattern that does not include delimiters.

The caret (^) means the start of the string. So, "/^Hello/" checks if the string starts with 'Hello'.

3fill in blank

hard

Fix the error in the pattern to check if the string contains only digits.

PHP

<?php
$string = "12345";
if (preg_match([1], $string)) {
    echo "Only digits.";
} else {
    echo "Contains other characters.";
}
?>

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

A"/\d*$/"

B"/^[0-9]*$/"

C"/\d+/"

D"/^[0-9]+$/"

Attempts:

3 left

💡 Hint

Common Mistakes

Using * which allows empty strings.

Not anchoring the pattern with ^ and $.

The pattern "/^[0-9]+$/" matches strings that contain only digits from start to end, with at least one digit.

4fill in blank

hard

Fill both blanks to create a pattern that matches strings ending with '.com' or '.org'.

PHP

<?php
$string = "example.com";
if (preg_match([1], $string) || preg_match([2], $string)) {
    echo "Valid domain.";
} else {
    echo "Invalid domain.";
}
?>

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

A"/\.com$/"

B"/\.net$/"

C"/\.org$/"

D"/\.edu$/"

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to escape the dot.

Using wrong domain endings like .net or .edu.

The patterns "/\.com$/" and "/\.org$/" check if the string ends with '.com' or '.org' respectively.

5fill in blank

hard

Fill all three blanks to create a pattern that matches a valid email address with letters, digits, dots, and underscores before '@'.

PHP

<?php
$email = "[e-mail]";
$pattern = "/^[[1]][2][[3]]+@example\.com$/";
if (preg_match($pattern, $email)) {
    echo "Valid email.";
} else {
    echo "Invalid email.";
}
?>

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

Aa-zA-Z0-9._

B+

C*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using + which requires at least one character in the middle part.

Not including all allowed characters in the class.

The pattern uses a character class [a-zA-Z0-9._], then * to allow zero or more characters, then the same character class again to match the email username part.