Question

How to create a function with an optional parameter in PHP

Answer 1

// optional parameter in PHP by giving the parameter a default value, usually null. 
// That makes the parameter optional when calling the function.

// Optional Parameter Using null

function greet($name = null) {
    if ($name !== null) {
        echo "Hello, $name" . "\n";
    } else {
        echo "Hello, guest" . "\n";
    }
}

greet("Nova"); 
greet();     



/*
run:

Hello, Nova
Hello, guest

*/

 

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Answer 2

// Optional Parameter With a Non‑Null Default

function connect($host = "localhost") {
    echo "Connecting to $host..." . "\n";
}

connect();              
connect("seek4info.com"); 
   


/*
run:

Connecting to localhost...
Connecting to seek4info.com...

*/

 

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Answer 3

// Multiple Optional Parameters

function createUser($name, $email = null, $role = "user") {
    echo "Name: $name\n";
    echo "Email: " . ($email ?? "not provided") . "\n";
    echo "Role: $role\n";
}

createUser("Zara");
createUser("Zara", "zara@collectivesolver.com", "admin");

   


/*
run:

Name: Zara
Email: not provided
Role: user
Name: Zara
Email: zara@collectivesolver.com
Role: admin

*/

 

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