How to Generate a Default Function Parameter in PHP
In this snippet, we will have a look at the process of generating a default function parameter (also known as the optional parameter).
Generating and Using a Default Function Parameter
The syntax of this parameter is as follows:
function greeting($name = "parameter_value")It is capable of accepting only one parameter (here it is the $name). It holds the value of the parameter.
The procedure of generating and using the default function parameter is illustrated in the examples below.
Example 1
<?php
function greeting($name = "W3docs")
{
echo "Welcome to $name ";
echo "\n";
}
greeting("W3d");
// Passing no value
greeting();
greeting("Computer Science Portal");
?>Welcome to W3d Welcome to W3docs Welcome to Computer Science Portal
Example 2
<?php
function welcome($first = "W3docs", $last = "Computer Science Portal for Everyone")
{
echo "Greeting: $first $last";
echo "\n";
}
welcome();
welcome("night_fury");
welcome("night_fury", "Contributor");
?>Greeting: W3docs Computer Science Portal for Everyone Greeting: night_fury Computer Science Portal for Everyone Greeting: night_fury Contributor
About Default Function Parameter
The prototype of the concept of the default function parameter is C++ style default argument values.
In PHP, you can provide default parameters in a way that once a parameter is not passed toward the function, it is still reachable inside the function with a pre-defined value. Note that default values are also known as optional parameters, as it is not a must to pass them to the function.