Use of Default Arguments in PHP

Use of default arguments is very common and helpful in programming. Default arguments provide a useful way for the smooth and correct execution of algorithms in the logic. I am going to share a professional usage of php default argument array in the codes.

I really love this method as it helps me a lot for merging user and default arguments in the different codes. You can say, it is one of Must Have Method, for every developer.

Let’s write a method chip_print which will print our output. I use this function regularly in my classes to get a quick print of string, variables and arrays.

Function chip_print

function chip_print( $var ) {
	echo "<pre>";
	print_r($var);
	echo "</pre>";
}

Function chip_parse_args

Now i am going to write the main method which will merge default arguments with user arguments.

function chip_parse_args( $args = array() ) {

	$defaults = array (
		'arg1'	=>	'default',
		'arg2'	=>	'default'
	);

	$result = array_merge( $defaults, $args );

	return $result;

}

You have noticed that i have used built-in function of PHP, array_merge.

Usage Example 1

You can use this function without passing any argument.

$result = chip_parse_args();
chip_print($result);

Output

Array
(
    [arg1] => default
    [arg2] => default
)

You have noticed that function has returned default values as we have passed not input to the method.

Usage Example 2

We will pass one argument to the method.

$args = array (
	'arg1'	=>	'modified1'
);
$result = chip_parse_args($args);
chip_print($result);

Output

Array
(
    [arg1] => modified1
    [arg2] => default
)

You have noticed that function has replaced argument 1 with the passed value.

Usage Example 3

We will pass two arguments as a test to the method.

$args = array (
	'arg1'	=>	'modified1',
	'arg2'	=>	'modified2'
);
$result = chip_parse_args($args);
chip_print($result);

Output

Array
(
    [arg1] => modified1
    [arg2] => modified2
)

You have noticed that function has replaced both arguments with the passed values.

Complete Tutorial

<?php

/*
|--------------
| Chip Print
|--------------
*/

function chip_print( $var ) {

	echo "<pre>";
	print_r($var);
	echo "</pre>";

}

/*
|--------------
| Chip Parse Arguments
|--------------
*/

function chip_parse_args( $args = array() ) {

	$defaults = array (
		'arg1'	=>	'default',
		'arg2'	=>	'default'
	);

	$result = array_merge( $defaults, $args );

	return $result;

}

/*
|--------------
| Example 1
|--------------
*/

$result = chip_parse_args();
chip_print($result);

/*
|--------------
| Example 2
|--------------
*/

$args = array (
	'arg1'	=>	'modified1'
);
$result = chip_parse_args($args);
chip_print($result);

/*
|--------------
| Example 3
|--------------
*/

$args = array (
	'arg1'	=>	'modified1',
	'arg2'	=>	'modified2'
);
$result = chip_parse_args($args);
chip_print($result);

?>

I hope you will like this tutorial and be master in using default array values in your PHP coding. Don’t forget to subscribe your email to stay updated with incoming articles, classes and tutorials. Your comments will also be helpful for writing best tutorials in future.

Download Tutorial File

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