How to create default function parameter in PHP?

The default parameter concept comes from C++ style default argument values, same as in PHP you can provide default parameters so that when a parameter is not passed to the function. Then it is still available within the function with a pre-defined value. This function also can be called optional parameter. Syntax:

function greeting($name=" parameter_value ")

Parameter: This function accepts a single parameter that is $name here, holds the parameter value. Below examples illustrate the procedure to create and use the default function parameter: Example 1:

php

<?php
    function greeting($name="GeeksforGeeks")
    {
        echo "Welcome to $name ";
        echo("\n");
    }
    greeting("Gfg");

    // Passing no value
    greeting();
    greeting("A Computer Science Portal");
?>

Output:

Welcome to Gfg 
Welcome to GeeksforGeeks 
Welcome to A Computer Science Portal 

Example 2:

php

<?php
    function welcome($first="GeeksforGeeks",
                     $last="A Computer Science Portal for Geeks")
                     {
                        echo "Greeting: $first $last";
                        echo("\n");
    }
    welcome();
    welcome("night_fury");
    welcome("night_fury","Contributor");
?>

Output:

Greeting: GeeksforGeeks A Computer Science Portal for Geeks
Greeting: night_fury A Computer Science Portal for Geeks
Greeting: night_fury Contributor