Programming PHP Operators in PHP

Operators in PHP

While trying to learn about PHP operators, the first question is What is operator? 

PHP Operators are symbols which operate one or more operands, just like in mathematical expressions.

PHP Operators

PHP operators can be grouped in the following categories:

  • Arithmetic Operators.
  • Assignment Operators.
  • Comparison Operators.
  • Incrementing/Decrementing Operators.
  • Logical Operators.
  • String Operators.
  • Array Operators.

PHP Arithmetic Operators

These operators are used to do arithmetic operations i.e. addition, substraction etc on operands (variables).  The explanation would be easier with the table below.

Operator Name Expression 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)

PHP Assignment Operators

These operators are used to write a value to a  variable.  The explanation would be easier with the table below. The basic assignment operator is “=”.

The value of an assignment expression is the final value assigned to the variable. In addition to the regular assignment operator “=”, some other assignment operators are combinations of an operator followed by an equal “=” sign.

  • += 
  • -=
  • *=
  • /=
  • %=

The explanation would be easier with the table below.

Expression Shorthand Description
$a = $a + $b $a+= $b Adds 2 numbers and assigns the result to the first.
$a = $a -$b $a-= $b Subtracts 2 numbers and assigns the result to the first.
$a = $a*$b $a*= $b Multiplies 2 numbers and assigns the result to the first.
$a = $a/$b $a/= $b Divides 2 numbers and assigns the result to the first.
$a = $a%$b $a%= $b Computes the modulus of 2 numbers and assigns the result to the first.

PHP Comparison Operators

Comparison operators allow to compare two values.
If you compare a number with a string or the comparison involves numerical strings, then each string is automatically converted to a number and the comparison performed numerically. These rules also apply to the switch statement. The type conversion does not take place when the comparison is === or !== as this involves comparing the type as well as the value.

Example Name Result
$a == $b Equal TRUE if $a is equal to $b after type juggling
$a === $b Identical TRUE if $a is equal to $b, and they are of the same type.
$a != $b Not equal TRUE if $a is not equal to $b after type juggling.
$a <> $b Not equal TRUE if $a is not equal to $b after type juggling.
$a !== $b Not identical TRUE if $a is not equal to $b, or they are not of the same type.
$a < $b Less than TRUE if $a is strictly less than $b.
$a > $b Greater than TRUE if $a is strictly greater than $b.
$a <= $b Less than or equal to TRUE if $a is less than or equal to $b.
$a >= $b Greater than or equal to TRUE if $a is greater than or equal to $b.
$a <=> $b Spaceship An integer less than, equal to, or greater than zero when $a is respectively less than, equal to, or greater than $b. Available as of PHP 7.

PHP Incrementing & Decrementing Operators

Increment and decrement operators are unary operators i.e. need only one operand that add or subtract one from their operand, respectively.

Result

Example Name
++$a Pre-increment
$a++ Post-increment
–$a Pre-decrement
$a– Post-decrement

PHP Logical Operators

An expression that has logical operator returns either 0 or 1 depending upon whether expression results true or false. Logical operators are generally used in decision making.

Result

Example Name
$a and $b And
$a or $b Or
$a xor $b Xor
! $a Not

PHP String Operators

String operators are of two types. The first is the concatenation operator “.”, which returns the concatenation of its right and left value(s). The second is the concatenating assignment operator “.=”, which appends the value  on the right side to the value on the left side.

<?php 
	$a = "Hello";
	$b = "World";
	echo $a . " " . $b;
	/* Result will be 
	*  Hello World
	*/

	$a .= " World"; // can be used as $a .= "".$b;
	echo $a;
	/* Result will be 
	*  Hello World
	*/
?>

PHP Array Operators

Operations on arrays are performed using Arrays Operators like Union, Equality, Identity, Inequality and Non-identity. The explanation would be easier with the table below

Result

Example Name
$x + $y Union
$x == $y Equality
$x === $y Identity
$x != $y Inequality

Read explained PHP Array Operators

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