Common autoloading mistakes in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to register an autoloader function.

PHP

<?php
spl_[1]('myAutoloader');
function myAutoloader($class) {
    include $class . '.php';
}
?>

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

Aregister

Binclude

Cautoload

Dload

Attempts:

3 left

💡 Hint

Common Mistakes

Using spl_register instead of spl_autoload_register

Using spl_load which does not exist

Using spl_include which is invalid

The correct function to register an autoloader is spl_autoload_register.

2fill in blank

medium

Complete the autoloader to correctly load class files from the 'classes' directory.

PHP

<?php
function myAutoloader($class) {
    include __DIR__ . '/[1]/' . $class . '.php';
}
spl_autoload_register('myAutoloader');

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Aclasses

Blib

Csrc

Dincludes

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong folder names like 'src' or 'lib' when files are in 'classes'

Forgetting to add the directory separator '/'

The class files are stored in the 'classes' directory, so the autoloader must include that folder.

3fill in blank

hard

Fix the error in the autoloader function to avoid fatal errors when the file does not exist.

PHP

<?php
function myAutoloader($class) {
    $file = __DIR__ . '/classes/' . $class . '.php';
    if ([1]($file)) {
        include $file;
    }
}
spl_autoload_register('myAutoloader');

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Ais_readable

Bis_dir

Cis_file

Dfile_exists

Attempts:

3 left

💡 Hint

Common Mistakes

Using is_dir which checks for directories, not files

Using is_readable without checking existence first

Not checking at all, causing fatal errors

Using file_exists checks if the file is present before including it, preventing errors.

4fill in blank

hard

Fill both blanks to create an autoloader that supports namespaces by converting backslashes to directory separators.

PHP

<?php
function myAutoloader($class) {
    $file = __DIR__ . '/classes/' . str_replace([1], [2], $class) . '.php';
    if (file_exists($file)) {
        include $file;
    }
}
spl_autoload_register('myAutoloader');

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A'\\'

B'/'

C'\\\'

Attempts:

3 left

💡 Hint

Common Mistakes

Using single backslash without escaping

Replacing with wrong characters

Not escaping backslash properly

Namespaces use backslashes '\\' which must be replaced with '/' for file paths.

5fill in blank

hard

Fill all three blanks to create a PSR-4 compliant autoloader that maps a base namespace to a base directory.

PHP

<?php
function myAutoloader($class) {
    $prefix = [1];
    $base_dir = __DIR__ . [2];
    $len = strlen($prefix);
    if (strncmp($prefix, $class, $len) !== 0) {
        return;
    }
    $relative_class = substr($class, $len);
    $file = $base_dir . str_replace([3], '/', $relative_class) . '.php';
    if (file_exists($file)) {
        include $file;
    }
}
spl_autoload_register('myAutoloader');

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

A'App\\'

B'/src/'

C'\\'

D'App\'

Attempts:

3 left

💡 Hint

Common Mistakes

Using single backslash in prefix without escaping

Wrong base directory path

Not replacing backslashes properly

The prefix is the base namespace 'App\\', the base directory is '/src/', and backslashes '\\' are replaced with slashes '/' in the relative class.