Boolean type behavior in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assign a boolean true value to the variable.

PHP

<?php
$flag = [1];
var_dump($flag);

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

ATrue

B"true"

Ctrue

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using "True" with uppercase T which is not recognized as boolean.

Using quotes around true, making it a string instead of boolean.

The correct boolean value in PHP is true (all lowercase). It represents the boolean true.

2fill in blank

medium

Complete the code to check if the variable is boolean using the correct function.

PHP

<?php
$value = false;
if ([1]($value)) {
    echo "It is boolean.";
} else {
    echo "It is not boolean.";
}

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

Ais_bool

Bis_true

Cboolval

Dis_boolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using is_boolean which does not exist in PHP.

Using boolval which converts to boolean but does not check type.

The function is_bool() checks if a variable is of boolean type in PHP.

3fill in blank

hard

Fix the error in the code to correctly convert a string to boolean.

PHP

<?php
$input = "false";
$boolValue = [1]($input);
var_dump($boolValue);

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

A(boolval)

Bbool

Cbooleanval

Dboolval

Attempts:

3 left

💡 Hint

Common Mistakes

Using bool as a function which causes error.

Using booleanval which does not exist.

The function boolval() converts a value to boolean in PHP. Casting with (bool) is also valid but not listed here.

4fill in blank

hard

Fill both blanks to create an array with keys as words and values as their boolean check.

PHP

<?php
$words = ["yes", "no", "true", "false"];
$result = [[1] => [2] for [1] in $words];

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

A"word"

Bboolval($word)

C$word

Dis_bool($word)

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the key which makes it a string literal.

Using is_bool which checks type but does not convert.

The key should be the variable $word and the value should be the boolean conversion boolval($word).

5fill in blank

hard

Fill all three blanks to create a filtered array with words whose boolean value is true.

PHP

<?php
$words = ["", "0", "1", "true"];
$filtered = array_filter($words, function($[1]) {
    return [2]($[3]);
});

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

Aitem

Bboolval

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inside and outside the function.

Using a function other than boolval for conversion.

The variable name in the function is $word. The function boolval converts it to boolean for filtering.