Operators are used to perform operations on variables and values.

PHP divides the operators in the following groups:

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

###### PHP 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 Result + Addition \$x + \$y Sum of \$x and \$y – Subtraction \$x – \$y Difference of \$x and \$y * Multiplication \$x * \$y Product of \$x and \$y / Division \$x / \$y Quotient of \$x and \$y % Modulus \$x % \$y Remainder of \$x divided by \$y ** Exponentiation \$x ** \$y Result of raising \$x to the \$y’th power (Introduced in PHP 5.6)

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$y = 6;

echo \$x + \$y;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$y = 6;

echo \$x – \$y;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$y = 6;

echo \$x * \$y;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$y = 6;

echo \$x / \$y;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$y = 6;

echo \$x % \$y;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 2;
\$y = 8;

echo \$x ** \$y;
?>

</body>
</html>

###### PHP Assignment Operators

The PHP assignment operators are used with numeric values to write 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.

 Assignment Same as… Description x = y x = y The left operand gets set to the value of the expression on the right 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

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
echo \$x;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 20;
\$x += 100;

echo \$x;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 50;
\$x -= 30;

echo \$x;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$x *= 10;

echo \$x;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$x /= 5;

echo \$x;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 15;
\$x %= 4;

echo \$x;
?>

</body>
</html>

###### PHP Comparison Operators

The PHP comparison operators are used to compare two values (number or string):

 Operator Name Example Result == Equal \$x == \$y Returns true if \$x is equal to \$y === Identical \$x === \$y Returns true if \$x is equal to \$y, and they are of the same type != Not equal \$x != \$y Returns true if \$x is not equal to \$y <> Not equal \$x <> \$y Returns true if \$x is not equal to \$y !== Not identical \$x !== \$y Returns true if \$x is not equal to \$y, or they are not of the same type > Greater than \$x > \$y Returns true if \$x is greater than \$y < Less than \$x < \$y Returns true if \$x is less than \$y >= Greater than or equal to \$x >= \$y Returns true if \$x is greater than or equal to \$y <= Less than or equal to \$x <= \$y Returns true if \$x is less than or equal to \$y

###### Equal Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = “100”;

var_dump(\$x == \$y); // returns true because values are equal
?>

</body>
</html>

###### Identical Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = “100”;

var_dump(\$x === \$y); // returns false because types are not equal
?>

</body>
</html>

###### Not equal Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = “100”;

var_dump(\$x != \$y); // returns false because values are equal
?>

</body>
</html>

###### Not equal Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = “100”;

var_dump(\$x <> \$y); // returns false because values are equal
?>

</body>
</html>

###### Not identical Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = “100”;

var_dump(\$x !== \$y); // returns true because types are not equal
?>

</body>
</html>

###### Greater than Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = 50;

var_dump(\$x > \$y); // returns true because \$x is greater than \$y
?>

</body>
</html>

###### Less than Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
\$y = 50;

var_dump(\$x < \$y); // returns true because \$x is less than \$y
?>

</body>
</html>

###### Greater than or equal to Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 50;
\$y = 50;

var_dump(\$x >= \$y); // returns true because \$x is greater than or equal to \$y
?>

</body>
</html>

###### Less than or equal to Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 50;
\$y = 50;

var_dump(\$x <= \$y); // returns true because \$x is less than or equal to \$y
?>

</body>
</html>

###### PHP Increment / Decrement Operators

The PHP increment operators are used to increment a variable’s value.

The PHP 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

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
echo \$x++;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
echo ++\$x;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
echo –\$x;
?>

</body>
</html>

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 10;
echo \$x–;
?>

</body>
</html>

###### PHP Logical Operators

The 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

###### And Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = 50;

if (\$x == 100 and \$y == 50) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

###### Or Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = 50;

if (\$x == 100 or \$y == 80) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

###### Xor Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = 50;

if (\$x == 100 xor \$y == 80) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

###### And Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = 50;

if (\$x == 100 && \$y == 50) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

###### Or Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = 100;
\$y = 50;

if (\$x == 100 || \$y == 80) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

###### Not Example

<!DOCTYPE html>

<html>
<body>

<?php
\$x = 100;

if (\$x !== 90) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

###### PHP String Operators

PHP has two operators that are specially designed for strings.

 Operator Name Example Result . Concatenation \$txt1 . \$txt2 Concatenation of \$txt1 and \$txt2 .= Concatenation assignment \$txt1 .= \$txt2 Appends \$txt2 to \$txt1

###### Concatenation Example

<!DOCTYPE html>
<html>
<body>

<?php
\$txt1 = “Robert”;
\$txt2 = ” Karamagia”;
echo \$txt1 . \$txt2;
?>

</body>
</html>

###### Concatenation assignment Example

<!DOCTYPE html>
<html>
<body>

<?php
\$txt1 = “Robert”;
\$txt2 = ” Karamagi”;
\$txt1 .= \$txt2;
echo \$txt1;
?>

</body>
</html>

###### PHP Array Operators

The PHP array operators are used to compare arrays.

 Operator Name Example Result + Union \$x + \$y Union of \$x and \$y == Equality \$x == \$y Returns true if \$x and \$y have the same key/value pairs === Identity \$x === \$y Returns true if \$x and \$y have the same key/value pairs in the same order and of the same types != Inequality \$x != \$y Returns true if \$x is not equal to \$y <> Inequality \$x <> \$y Returns true if \$x is not equal to \$y !== Non-identity \$x !== \$y Returns true if \$x is not identical to \$y

###### Union Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = array(“a” => “red”, “b” => “green”);
\$y = array(“c” => “blue”, “d” => “yellow”);

print_r(\$x + \$y); // union of \$x and \$y
?>

</body>
</html>

###### Equality Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = array(“a” => “red”, “b” => “green”);
\$y = array(“b” => “green”, “a” => “red”);

var_dump(\$x == \$y);
?>

</body>
</html>

###### Identity Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = array(“a” => “red”, “b” => “green”);
\$y = array(“b” => “green”, “a” => “red”);

var_dump(\$x === \$y);
?>

</body>
</html>

###### Inequality Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = array(“a” => “red”, “b” => “green”);
\$y = array(“c” => “blue”, “d” => “yellow”);

var_dump(\$x != \$y);
?>

</body>
</html>

###### Inequality Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = array(“a” => “red”, “b” => “green”);
\$y = array(“c” => “red”, “d” => “green”);

var_dump(\$x <> \$y);
?>

</body>
</html>

###### Non-identity Example

<!DOCTYPE html>
<html>
<body>

<?php
\$x = array(“a” => “red”, “b” => “green”);
\$y = array(“a” => “red”, “b” => “green”);

var_dump(\$x !== \$y);
?>

</body>
</html>