PHP Function Parameters

Summary: Now, friends, in this tutorial we will show you how to learn function parameters and in this case, you will pass arguments by value and reference, and we will show you step by step how to do this.

The argument list, which is a list of expressions separated by commas, is one way that information can be supplied to functions. Prior to actually calling the function, the inputs are eagerly evaluated ( from left to right ).

PHP accepts default argument values, passing by reference, and passing by value as additional argument types. Named Arguments and variable-length argument lists are also supported.

Introduction to the PHP Function Parameters

A function may have 0 parameters or more:

 

?php

function function_name ( parameter_list ) 
{
}

 

Now friends If a function has more than one parameter, you will need to separate them using a comma (,) note that and write the code.

The following example defines the concat() function, which combines two strings into one.

 

?php

function concat($str1, $str2)
{
	return $str1 . $str2;
}

 

$str1 and $str2 are the two parameters for the concat() function.

Two arguments that match the parameters must be given when using the concat() function. For instance:

 

?php
function concat($str1, $str2)
{
	return $str1 . $str2;
}

$greeting = concat( 'Welcome ', 'Admin' );
echo $greeting;

 

The $str1 will accept the first parameter in this example, "Welcome," and the $str2 will accept the second input, "Admin."

If the amount of arguments you supply to a function in PHP is less than the number of parameters, an error will be raised. For instance:

 

?php

function concat($str1, $str2)
{
	return $str1 . $str2;
}


$greeting = concat('Welcome');
echo $greeting;

 

To make the code more understandable when passing many parameters to a method, you can divide the list vertically like in the following example:

 

?php

function concat($str1, $str2)
{
	return $str1 . $str2;
}

$greeting = concat(
	'Welcome ',
	'Home'
);

echo $greeting;

 

It’s a good practice to list arguments vertically when the argument list is long.

Trailing comma (,)

Since PHP 7.0, the PHP interpreter will ignore a trailing comma (,) in the argument list. For instance:

 

$greeting = concat(
	'Welcome ',
	'Home',
);

 

Hey gus now starting from PHP 8.0, you can place the trailing comma (,) in the parameter list like this:

 

function concat(
	$str1,
	$str2,
) {
	return $str1 . $str2;
}

 

Passing arguments by values

Now, as the techdataz team, we would like you to consider the following example:

 

?php

$counter = 1;
function increase($value)
{
	$value+= 1;
	echo $value. 
; // 2
}

// increase the counter
increase($counter);

echo $counter . <"br>; // 1

 

Output:

 

2
1

 

How it operates

1. The $counter variable should first be defined and initialized to one.
2. Next, specify the increase() function, which displays the parameter after being increased by one.
3. Third, invoke the increment() function and supply it with the $counter variable.
4. The $counter variable should then be displayed.

The increase() function adds one to the value of the $counter variable when it receives a $counter argument. As a result, you will see two when you display the value of the $counter inside the function.

The counter value is still one after the function call, though. This indicates that the $counter variable is not increased outside of the increase() function. When the $counter variable is passed to the increment() function, a copy of the $counter variable is created and adjusted. The initial variable is unaffected. There is no change to the $counter variable.

It is called passed by value when an argument's value is modified inside a function yet remains outside of it.

In PHP, arguments are often provided as values. You have to give the arguments by reference if you wish a function to alter values.

Passing arguments by reference

In the function definition, you must prefix the parameter name with the operator (&) in order to pass an argument via reference:

 

?php

$counter = 1;
function increase( &$value )
{
	$value += 1;
	echo $value . <1"br>; // 2
}

// increase the counter
increase($counter);

echo $counter . <1"br>; // 2

 

Output:

 

2
2

 

In the above example, the $counter variable's change has an impact both inside and outside the function.

Pass arguments by reference

1. Parameters should be separated by commas (,). The PHP interpreter ignores the trailing comma (,) in parameter lists since PHP 8.0.
2. PHP passes arguments by value by default.
3. To send arguments by reference, attach parameters with an ampersand (&).

By default, function arguments are passed by value (so that if the value of the argument inside the function is changed, it won't change outside the function). To allow a function to modify its arguments, they must be passed by reference.

To ensure that an argument to a function is always passed by reference, add an ampersand (&) to the beginning of the argument name in the function definition:

Friends, for example, giving the command of the code functions in a sequential manner. Please visit: PHP Function Parameters Now, if you are stuck or unable to do anything, please e-mail us and contact us. This is the link we shared with you below: you need to examine it in detail from the right source. We always provide you with the details of the right source.