Union types in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a function that accepts an integer or a string.

PHP

<?php
function example([1] $value) {
    return $value;
}
?>

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

Aint|string

Bint&string

Cint

Dint|string|null

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' instead of '|' for union types.

Adding 'null' when not required.

Using only one type instead of a union.

The union type int|string allows the function to accept either an integer or a string.

2fill in blank

medium

Complete the code to declare a property that can hold either a float or null.

PHP

<?php
class Sample {
    public [1] $price;
}
?>

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

Afloat&null

Bfloat|null

Cfloat

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' instead of '|' for union types.

Forgetting to include null for nullable properties.

The property type float|null means it can be a float or null.

3fill in blank

hard

Fix the error in the function parameter type declaration to accept either an array or a string.

PHP

<?php
function process([1] $input) {
    // process input
}
?>

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

Aarray|string

Barray&string

Carray

Darray|string|null

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' instead of '|' for union types.

Adding null when not needed.

The correct union type is array|string to accept either type.

4fill in blank

hard

Fill both blanks to declare a function that returns either an int or a float and accepts a string or int parameter.

PHP

<?php
function calculate([1] $value): [2] {
    // calculation logic
}
?>

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

Astring|int

Bint|float

Cfloat|string

Dint

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up parameter and return types.

Using intersection '&' instead of union '|'.

The parameter type string|int allows either type as input, and the return type int|float allows either type as output.

5fill in blank

hard

Fill all three blanks to create a class property with a union type, a constructor parameter with a union type, and a method return type union.

PHP

<?php
class Data {
    private [1] $info;

    public function __construct([2] $info) {
        $this->info = $info;
    }

    public function getInfo(): [3] {
        return $this->info;
    }
}
?>

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

Astring|int

Dint|string|null

Attempts:

3 left

💡 Hint

Common Mistakes

Using different union types in property and methods.

Including null when not needed.

Using intersection '&' instead of union '|'.

All three use the union type string|int to allow flexibility in the property, constructor parameter, and method return type.