PHP Operators

An operator is a symbol that specifies an action to perform in an expression, for example, the '+' symbol in the expression '1 + 2' would add the two numbers together to produce a result. This type of operator is known as an arithmetic operator, however, there are also other groups of operators within PHP that will be explained below.

Arithmetic Operators

Arithmetic operators allow for mathematical calculations to be carried out within a PHP script.

The following examples show each of these operators in action.

// Variables to use in expressions.
$a = 10;
$b = 20;
$c = 0;

$c = $a + $b;   // c will equal 30.
$c = $b - $a;   // c will equal 10.
$c = $a * $b;   // c will equal 200.
$c = $b / $a;   // c will equal 2.
$c = $b % $a;   // c will equal 0.

Assignment Operators

Assignment Operators in PHP are used to assign values to a variable, the most basic of which is '='. Here, the '=' symbol means 'gets set to' rather than 'equals', so in the expression '$x = $y', 'x' gets set to 'y'. The Arithmetic Operator symbols can be combined with '=' to form the Assignment Operators used in the following examples.

$a = 10; // a gets set to 10.

$b = 2;
$b += 5; // b gets set to 7.

$c = 10;
$c -= 4; // c gets set to 6.

$d = 2;
$d *= 2; // d gets set to 4.

$e = 20;
$e /= 5; // e gets set to 4.

$f = 5;
$f %= 2; // f gets set to 1.

String Operators

Below are examples of these two string operators, both of which produce the same result, a single string containing 'Hello world'.

$a = "Hello";
$b = $a . " world";

$x = "Hello";
$x .= " world";

Relational Operators

Relational operators compare two values and are used, for example, in 'if' statements, which are described in the next section on Decision Making. The result of the comparison is either True or False.

Logical Operators

Logical operators are used where you want to test more than one condition at the same time, for example, in an 'if' statement.