Script execution and memory reset in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the value of the variable.

PHP

<?php
$counter = 5;
echo [1];
?>

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

Acounter

B$counter

C5

Decho

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the $ sign before the variable name.

Trying to print the variable name as a string without $.

The variable $counter holds the value 5. To print it, use echo $counter;.

2fill in blank

medium

Complete the code to reset the variable $count to zero.

PHP

<?php
$count = 10;
$count = [1];
echo $count;
?>

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

Anull

Bfalse

C0

D''

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning null instead of zero.

Assigning an empty string which is not a number.

To reset a numeric variable to zero, assign 0 to it.

3fill in blank

hard

Fix the error in the code to correctly unset the variable $temp.

PHP

<?php
$temp = 100;
[1]($temp);
echo isset($temp) ? 'Exists' : 'Unset';
?>

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

Aunset

Bdelete

Cremove

Dclear

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent functions like delete or remove.

Trying to assign null instead of unsetting.

In PHP, unset() is used to delete a variable from memory.

4fill in blank

hard

Fill both blanks to create an array with keys as numbers and values as their squares, but only for numbers greater than 3.

PHP

<?php
$numbers = range(1, 5);
$squares = array_combine(array_filter($numbers, function($n) {
    return $n [2] 3;
}), array_map(function($n) {
    return $n[1]2;
}, array_filter($numbers, function($n) {
    return $n [2] 3;
}));
print_r($squares);
?>

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

A**

B+

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of power operator.

Using < instead of > in condition.

The ** operator calculates powers in PHP. The condition $n > 3 filters numbers greater than 3.

5fill in blank

hard

Fill all three blanks to create an associative array with uppercase keys and values greater than zero.

PHP

<?php
$data = ['a' => 1, 'b' => -2, 'c' => 3];
$result = array_filter(array_combine(array_map(function($k) {
    return [1];
}, array_keys($data)), [3]), function($v) {
    return $v [2] 0;
});
print_r($result);
?>

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

Astrtoupper($k)

B>

Carray_values($data)

Darray_keys($data)

Attempts:

3 left

💡 Hint

Common Mistakes

Using array_keys($data) instead of values for filtering.

Using < instead of > in condition.

strtoupper($k) converts keys to uppercase. The condition > 0 filters positive values. array_values($data) provides the values for filtering.