PHP Assignment Operators

This tutorial will teach you about the most common PHP assignment operators.

The assignment operator in PHP is represented by the = symbol. The syntax of the assignment operator is shown below:

$variable_name = expression;

A variable to which you want to assign a value is on the left side of the assignment operator (=). A value or an expression is placed on the right side of the assignment operator (=).

When the assignment operator (=) is used, PHP evaluates the expression on the right side first and then assigns the result to the variable on the left side. As an example:

$x = 10;
$y = 20;
$total = $x + $y;

In this example, we assigned a value of 10 to $x, a value of 20 to $y, and the sum of $x and $y to $total.

In this case, the assignment expression returns a value assigned, which is the result of the expression:

$variable_name = expression;

This means you can use multiple assignment operators in a single statement, such as this:

$x = $y = 20;

PHP evaluates the right-most expression first in this case:

$y = 20

The value of the variable $y is 20.

PHP assigns 20 to $x because the assignment expression $y = 20 returns 20. Following the assignments, $x and $y both equal 20.

Arithmetic assignment operators

You may want to increase a variable by a specific amount from time to time. As an example:

$counter = 1;
$counter = $counter + 1;

This is how it works.

To begin, $counter is set to 1.
Then, multiply $counter by 1 and assign the result to $counter.
The value of $counter after the assignments is 2.

PHP includes the arithmetic assignment operator +=, which can perform the same function but with less code. As an example:

$counter = 1;
$counter += 1;

The expression $counter += 1 corresponds to the expression $counter = $counter + 1.

Other arithmetic assignment operators are available in PHP in addition to the += operator. The table below depicts all of the arithmetic assignment operators:

Operator	Example	Equivalent	Operation
+=	$x += $y	$x = $x + $y	Addition
-=	$x -= $y	$x = $x – $y	Subtraction
*=	$x *= $y	$x = $x * $y	Multiplication
/=	$x /= $y	$x = $x / $y	Division
%=	$x %= $y	$x = $x % $y	Modulus
**=	$z **= $y	$x = $x ** $y	Exponentiation

Concatenation assignment operator

To concatenate two strings, PHP employs the concatenation operator (.). As an example:

<?php 

$greeting = 'Hello ';
$name = 'John';

$greeting = $greeting . $name;

echo $greeting;

Output

Hello John

You can concatenate two strings and assign the result string to a variable by using the concatenation assignment operator. As an example:

<?php 

$greeting = 'Hello ';
$name = 'John';

$greeting .= $name;

echo $greeting;