Common validation patterns in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if a variable is set.

PHP

<?php
if ([1](
  $name
)) {
  echo "Name is set.";
} else {
  echo "Name is not set.";
}
?>

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

Aisset

Bempty

Cis_null

Dis_string

Attempts:

3 left

💡 Hint

Common Mistakes

Using empty() which returns true if the variable is empty, not just set.

Using is_null() which checks if variable is null but does not check if it is set.

The isset function checks if a variable is set and is not null.

2fill in blank

medium

Complete the code to validate if a string contains only digits.

PHP

<?php
if ([1]($input)) {
  echo "Input is numeric.";
} else {
  echo "Input is not numeric.";
}
?>

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

Ais_numeric

Bis_string

Cctype_digit

Dpreg_match

Attempts:

3 left

💡 Hint

Common Mistakes

Using is_numeric() which allows decimal points and signs.

Using preg_match without a proper pattern.

The ctype_digit function checks if all characters in the string are digits.

3fill in blank

hard

Fix the error in the code to validate an email address.

PHP

<?php
$email = "[e-mail]";
if (filter_var($email, [1])) {
  echo "Valid email.";
} else {
  echo "Invalid email.";
}
?>

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

AFILTER_VALIDATE_INT

BFILTER_DEFAULT

CFILTER_SANITIZE_EMAIL

DFILTER_VALIDATE_EMAIL

Attempts:

3 left

💡 Hint

Common Mistakes

Using FILTER_SANITIZE_EMAIL which only cleans the email but does not validate.

Using FILTER_VALIDATE_INT which is for integers.

FILTER_VALIDATE_EMAIL is used with filter_var to check if the email is valid.

4fill in blank

hard

Fill both blanks to create an array of words longer than 3 characters.

PHP

<?php
$words = ['cat', 'house', 'dog', 'elephant'];
$longWords = array_filter($words, function($word) {
  return strlen($word) [1] [2];
});
print_r($longWords);
?>

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

A>

B<

C3

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' causing wrong filtering.

Using 5 instead of 3 changing the condition.

The code filters words with length greater than 3 using strlen($word) > 3.

5fill in blank

hard

Fill all three blanks to create an associative array of words and their lengths for words longer than 4.

PHP

<?php
$words = ['apple', 'bat', 'carrot', 'dog'];
$lengths = array_filter(array_combine(
  array_map(function($word) { return [1]; }, $words),
  array_map(function($word) { return [2]; }, $words)
), function($len) { return $len [3] 4; });
print_r($lengths);
?>

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

A$word

Bstrlen($word)

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' in the filter condition.

Using wrong variable names in map functions.

The code maps words as keys and their lengths as values, then filters lengths greater than 4.