# PHP Tutorial: Operators

#### Operators

Operators are used to perform operations on variables and values.

PHP has many operators which are divided into following categories:

• Arithmetic operators
• Assignment operators
• Comparison operators
• Increment/Decrement operators
• Logical operators
• String operators
• Array operators

Arithmetic Operators

The PHP arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc.

 Operator Name Example + Addition 2+4 - Substraction 6-2 * Multiplication 5 * 3 / Division 15 / 3 % Modulus 43 % 10

Example

<?php

\$subtraction = 6 - 2;

\$multiplication = 5 * 3;

\$division = 15 / 3;

\$modulus = 5 % 2;

echo "Perform subtraction: 6 - 2 = ".\$subtraction."<br />";

echo "Perform multiplication:  5 * 3 = ".\$multiplication."<br />";

echo "Perform division: 15 / 3 = ".\$division."<br />";

echo "Perform modulus: 5 % 2 = " . \$modulus. ". Modulus is the remainder after the division operation has been performed.

In this case it was 5 / 2, which has a remainder of 1.";

?>

Output:

Perform addition: 2 + 4 = 6

Perform subtraction: 6 - 2 = 4

Perform multiplication: 5 * 3 = 15

Perform division: 15 / 3 = 5

Perform modulus: 5 % 2 = 1. Modulus is the remainder after the division operation has been performed. In this case it was 5 / 2, which has a remainder of 1.

Assignment Operators

The PHP assignment operators are used with numeric values to assign a value to a variable.

The basic assignment operator in PHP is "=". It means that the left operand gets set to the value of the assignment expression on the right.

 Operator Name Example Equivalent Operation += Plus Equals \$x += 2; \$x = \$x + 2; -= Minus Equals \$x -= 4; \$x = \$x - 4; *= Multiply Equals \$x *= 3; \$x = \$x * 3; /= Divide Equals \$x /= 2; \$x = \$x / 2; %= Modulo Equals \$x %= 5; \$x = \$x % 5; .= Concatenate Equals \$my_str.="hello"; \$my_str = \$my_str . "hello";

PHP Comparison Operators

Comparisons are used to check the relationship between variables/values. Comparison operators are used inside conditional statements and evaluate to either true or false. Here are the most important comparison operators of PHP.

 Operator Name Example == Equal \$x == \$y === Identical \$x === \$y != Not equal \$x != \$y <> Not equal \$x <> \$y !== Not identical \$x !== \$y > Greater than \$x > \$y < Less than \$x < \$y >= Greater than or equal to \$x >= \$y <= Less than or equal to \$x <= \$y

Increment / Decrement Operators

The PHP increment operators are used to increment a variable's value and the decrement operators are used to decrement a variable's value.

 Operator Name Description ++\$x Pre-increment Increments \$x by one, then returns \$x \$x++ Post-increment Returns \$x, then increments \$x by one --\$x Pre-decrement Decrements \$x by one, then returns \$x \$x-- Post-decrement Returns \$x, then decrements \$x by one

Logical Operators

PHP logical operators are used to combine conditional statements.

 Operator Name Example Result and And \$x and \$y True if both \$x and \$y are true or Or \$x or \$y True if either \$x or \$y is true xor Xor \$x xor \$y True if either \$x or \$y is true, but not both && And \$x && \$y True if both \$x and \$y are true || Or \$x || \$y True if either \$x or \$y is true ! Not !\$x True if \$x is not true

String Operators

There are two operators that are specially designed for strings.

 Operator Name Example . Concatenation \$txt1 . \$txt2 .= Concatenation assignment \$txt1 .= \$txt2

Array Operators

The PHP array operators are used to compare arrays.

 Operator Name Example + Union \$x + \$y == Equality \$x == \$y === Identity \$x === \$y != Inequality \$x != \$y <> Inequality \$x <> \$y !== Non-identity \$x !== \$y

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