Type juggling in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to convert the string to an integer.

PHP

<?php
$value = "123";
$number = ([1])$value;
echo gettype($number); // outputs 'integer'
?>

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

Aint

Bstring

Cbool

Dfloat

Attempts:

3 left

💡 Hint

Common Mistakes

Using (string) instead of (int) will keep the value as a string.

Using (bool) will convert to true or false, not a number.

In PHP, casting a string to int converts it to an integer type.

2fill in blank

medium

Complete the code to check if the string '10 apples' equals the number 10 using ==.

PHP

<?php
$result = ('10 apples' [1] 10);
echo $result ? 'true' : 'false';
?>

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

A!==

B===

C!=

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using === will return false because types differ.

Using != or !== will check for inequality, not equality.

The == operator in PHP compares values after type juggling, so '10 apples' == 10 is true.

3fill in blank

hard

Fix the error in the code to correctly add a string number and an integer.

PHP

<?php
$a = "5";
$b = 3;
$sum = $a [1] $b;
echo $sum; // should output 8
?>

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

A*

B.

C+

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using . will concatenate strings, resulting in '53' instead of 8.

Using - or * will perform subtraction or multiplication, not addition.

The + operator adds numbers. PHP converts the string '5' to number 5 automatically.

4fill in blank

hard

Fill both blanks to create an array with keys as strings and values as integers using type juggling.

PHP

<?php
$items = ["1" => 100, "2" => 200];
foreach ($items as $key => $value) {
    echo (int) $key [1] $value . "\n";
}
?>

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

A+

B.

C-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using . will join numbers as strings, not add them.

Using - or * will perform subtraction or multiplication, not addition.

Casting the string key to int and adding the value sums numbers correctly.

5fill in blank

hard

Fill all three blanks to filter an array of strings, keeping only those that convert to integers greater than 10.

PHP

<?php
$values = ["5", "15", "abc", "20"];
$result = array_filter($values, function($val) {
    return (int) $val [1] 10;
});
print_r($result);
?>

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

A==

B>

C<

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using == will keep only values equal to 10, not greater.

Using < or != will filter incorrectly.

The > operator filters values where the integer conversion is greater than 10.