Why string functions matter in PHP - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to convert the string to uppercase.

PHP

<?php
$text = "hello world";
echo [1]($text);
?>

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

Astrtolower

Bstrtoupper

Cstrlen

Dsubstr

Attempts:

3 left

💡 Hint

Common Mistakes

Using strtolower will convert to lowercase, not uppercase.

Using strlen returns the length, not the changed string.

The strtoupper function converts all characters in a string to uppercase.

2fill in blank

medium

Complete the code to find the length of the string.

PHP

<?php
$text = "hello";
$length = [1]($text);
echo $length;
?>

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

Astrlen

Bsubstr

Cstrpos

Dstrtoupper

Attempts:

3 left

💡 Hint

Common Mistakes

Using strtoupper changes case but does not count characters.

Using strpos finds position of a substring, not length.

The strlen function returns the number of characters in a string.

3fill in blank

hard

Fix the error in the code to get the first 3 characters of the string.

PHP

<?php
$text = "Programming";
echo [1]($text, 0, 3);
?>

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

Astrlen

Bstrpos

Cstrtoupper

Dsubstr

Attempts:

3 left

💡 Hint

Common Mistakes

Using strlen returns length, not a substring.

Using strpos finds position, not substring.

The substr function extracts a part of the string starting at a position with a given length.

4fill in blank

hard

Fill both blanks to check if the word 'cat' is in the string and print its position.

PHP

<?php
$text = "The cat is sleeping.";
$pos = [1]($text, 'cat');
if ($pos !== [2]) {
    echo "Found at position: $pos";
} else {
    echo "Not found.";
}
?>

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

Astrpos

Bfalse

Ctrue

Dstrlen

Attempts:

3 left

💡 Hint

Common Mistakes

Checking against true instead of false causes wrong results.

Using strlen instead of strpos does not find position.

strpos finds the position of a substring. It returns false if not found, so we check against false.

5fill in blank

hard

Fill both blanks to create a new string with the first letter uppercase and the rest lowercase.

PHP

<?php
$text = "hELLO";
$newText = [1]([2]($text));
echo $newText;
?>

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

Aucfirst

Bstrtolower

Cstrtoupper

Dstrlen

Attempts:

3 left

💡 Hint

Common Mistakes

Using strtoupper first makes all letters uppercase.

Not converting to lowercase first keeps unwanted uppercase letters.

First, convert the whole string to lowercase with strtolower, then uppercase the first letter with ucfirst. The strtoupper option is a distractor here.