Named arguments in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to call the function using a named argument for name.

PHP

<?php
function greet(string $name) {
    echo "Hello, $[1]!";
}
greet(name: "Alice");
?>

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

AAlice

Bgreet

Cname

Decho

Attempts:

3 left

💡 Hint

Common Mistakes

Using the function name instead of the parameter name.

Using the argument value instead of the parameter name.

The function uses the parameter name. Using name as a named argument matches the parameter.

2fill in blank

medium

Complete the function call using a named argument for age.

PHP

<?php
function showAge(int $age) {
    echo "Age: $[1]";
}
showAge(age: 30);
?>

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

AshowAge

Bage

C30

Dint

Attempts:

3 left

💡 Hint

Common Mistakes

Using the function name instead of the parameter name.

Using the argument value instead of the parameter name.

The named argument age matches the function parameter age.

3fill in blank

hard

Fix the error by completing the function call with the correct named argument for city.

PHP

<?php
function printCity(string $city) {
    echo "City: $[1]";
}
printCity(city: "Paris");
?>

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

Astring

BprintCity

CParis

Dcity

Attempts:

3 left

💡 Hint

Common Mistakes

Using the function name instead of the parameter name.

Using the argument value instead of the parameter name.

The named argument must match the parameter city to avoid errors.

4fill in blank

hard

Fill both blanks to call the function with named arguments for firstName and lastName.

PHP

<?php
function fullName(string $firstName, string $lastName) {
    echo "Name: $[1] $[2]";
}
fullName([1]: "John", [2]: "Doe");
?>

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

AfirstName

BlastName

CJohn

DDoe

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping parameter names.

Using argument values as parameter names.

The named arguments must match the parameter names firstName and lastName.

5fill in blank

hard

Fill all three blanks to call the function with named arguments for title, author, and year.

PHP

<?php
function bookInfo(string $title, string $author, int $year) {
    echo "Book: $[1], Author: $[2], Year: $[3]";
}
bookInfo([1]: "1984", [2]: "Orwell", [3]: 1949);
?>

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

Atitle

Bauthor

Cyear

Dbook

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect parameter names.

Mixing up the order of named arguments.

Named arguments must match the parameter names title, author, and year exactly.

Practice

1.

What is the main benefit of using named arguments in PHP functions?

easy

A. Named arguments make functions run faster.

B. You must always provide all arguments in order.

C. You can specify arguments by name and change their order.

D. They allow you to define new functions inside existing ones.

Solution

1. Step 1: Understand named arguments concept

   Named arguments let you specify function parameters by their names instead of position.

2. Step 2: Identify the benefit

   This allows changing the order of arguments and skipping optional ones, improving readability.

3. Final Answer:

   You can specify arguments by name and change their order. -> Option C

4. Quick Check:

   Named arguments = specify by name and reorder [OK]

Hint: Named arguments let you reorder parameters by name [OK]

Common Mistakes:

• Thinking named arguments speed up execution
• Believing all arguments must be given in order
• Confusing named arguments with function definitions

2.

Which of the following is the correct syntax to call a function greet with named arguments name and age?

function greet($name, $age) { return "Hello $name, you are $age."; }

easy

A. greet("Alice", age: 30);

B. greet(name = "Alice", age = 30);

C. greet(age => 30, name => "Alice");

D. greet(name: "Alice", age: 30);

Solution

1. Step 1: Recall named argument syntax in PHP

   Named arguments use the syntax paramName: value when calling functions.

2. Step 2: Check each option

   greet(name: "Alice", age: 30); uses name: "Alice" and age: 30, which is correct syntax.

3. Final Answer:

   greet(name: "Alice", age: 30); -> Option D

4. Quick Check:

   Named argument syntax = paramName: value [OK]

Hint: Use colon : for named arguments in calls [OK]

Common Mistakes:

• Using => instead of : for named arguments
• Using = instead of : in calls
• Mixing positional and named arguments incorrectly

3.

What will be the output of the following PHP code?

function describe($color, $shape) {
    return "A $color $shape.";
}
echo describe(shape: "circle", color: "red");

medium

A. A red circle.

B. A red.

C. Syntax error.

D. A circle red.

Solution

1. Step 1: Understand named argument order

   Named arguments allow changing the order of parameters when calling the function.

2. Step 2: Substitute values in function

   Here, shape is "circle" and color is "red". The return string is "A $color $shape.", so it becomes "A red circle.".

3. Final Answer:

   A red circle. -> Option A

4. Quick Check:

   Named arguments reorder parameters = "A red circle." [OK]

Hint: Named arguments reorder parameters without error [OK]

Common Mistakes:

• Assuming order must match function definition
• Expecting syntax error from reordered named arguments
• Mixing up parameter names and values

4.

Identify the error in the following PHP code using named arguments:

function multiply($x, $y) {
    return $x * $y;
}
echo multiply(y: 5, 3);

medium

A. Function multiply is undefined.

B. Positional argument after named argument causes error.

C. Missing colon in named argument syntax.

D. No error; code runs fine.

Solution

1. Step 1: Check argument order rules

   In PHP, positional arguments must come before named arguments when calling a function.

2. Step 2: Analyze the call

   The call uses a named argument y: 5 first, then a positional argument 3, which is invalid syntax.

3. Final Answer:

   Positional argument after named argument causes error. -> Option B

4. Quick Check:

   Positional args must precede named args [OK]

Hint: Positional args must come before named args [OK]

Common Mistakes:

• Placing positional arguments after named arguments
• Forgetting colon in named argument
• Assuming named arguments can be mixed in any order

5.

Given the function below, which call correctly uses named arguments to skip the optional country parameter and specify city only?

function locationInfo(string $city, string $country = "USA") {
    return "$city, $country";
}

hard

A. locationInfo(city: "Boston");

B. locationInfo("Boston", country: "Canada");

C. locationInfo(city: "Boston", country: "Canada");

D. locationInfo(country: "Canada", city: "Boston");

Solution

1. Step 1: Understand optional parameters and named arguments

   The country parameter has a default value, so it can be skipped.

2. Step 2: Identify call that skips country and sets city

   locationInfo(city: "Boston"); calls locationInfo(city: "Boston"), skipping country and using default "USA".

3. Final Answer:

   locationInfo(city: "Boston"); -> Option A

4. Quick Check:

   Skip optional params by omitting them in named args [OK]

Hint: Skip optional params by not naming them [OK]

Common Mistakes:

• Trying to skip required parameters
• Providing positional argument after named argument
• Specifying optional parameter unnecessarily