PHP Operators

In PHP, operators are special symbols used to perform operations on variables and values. Operators help you perform a variety of tasks, such as mathematical calculations, string manipulations, logical comparisons, and more. Understanding operators is essential for writing effective and efficient PHP code. PHP operators are categorized into several types:

Let us now learn about each of these operators in detail.

1. Arithmetic Operators

Arithmetic operators are used to perform basic arithmetic operations like addition, subtraction, multiplication, division, and modulus.

Note: The exponentiation has been introduced in PHP 5.6. 

Example: This example explains the arithmetic operators in PHP.

<?php
// Define two numbers
$x = 10;
$y = 3;

// Addition
echo "Addition: " . ($x + $y) . "\n";

// Subtraction
echo "Subtraction: " . ($x - $y) . "\n";

// Multiplication
echo "Multiplication: " . ($x * $y) . "\n";

// Division
echo "Division: " . ($x / $y) . "\n";

// Exponentiation
echo "Exponentiation: " . ($x ** $y) . "\n";

// Modulus
echo "Modulus: " . ($x % $y) . "\n";
?>

Addition: 13
Subtraction: 7
Multiplication: 30
Division: 3.3333333333333
Exponentiation: 1000
Modulus: 1

2. Logical Operators

Logical operators are used to operate with conditional statements. These operators evaluate conditions and return a boolean result (true or false).

Example: This example describes the logical & relational operators in PHP.

<?php
$x = 50;
$y = 30;
  if ($x == 50 and $y == 30)
      echo "and Success \n";

  if ($x == 50 or $y == 20)
      echo "or Success \n";

  if ($x == 50 xor $y == 20)
      echo "xor Success \n";

  if ($x == 50 && $y == 30)
      echo "&& Success \n";

  if ($x == 50 || $y == 20)
      echo "|| Success \n";

  if (!$z)
      echo "! Success \n";
?> 

and Success 
or Success 
xor Success 
&& Success 
|| Success 
! Success 
 

3. Comparison Operators

Comparison operators are used to compare two values and return a Boolean result (true or false).

Example: This example describes the comparison operator in PHP.

<?php
  $a = 80;
  $b = 50;
  $c = "80";

  // Here var_dump function has been used to 
  // display structured information. We will learn 
  // about this function in complete details in further
  // articles.
  var_dump($a == $c) + "\n";
  var_dump($a != $b) + "\n";
  var_dump($a <> $b) + "\n";
  var_dump($a === $c) + "\n";
  var_dump($a !== $c) + "\n";
  var_dump($a < $b) + "\n";
  var_dump($a > $b) + "\n";
  var_dump($a <= $b) + "\n";
  var_dump($a >= $b);
?>

bool(true)

Warning: A non-numeric value encountered in /home/guest/sandbox/Solution.php on line 10
bool(true)

Warning: A non-numeric value encountered in /home/guest/sandbox/Solution.php on line 11
...

4. Conditional or Ternary Operators

These operators are used to compare two values and take either of the results simultaneously, depending on whether the outcome is TRUE or FALSE. These are also used as a shorthand notation for the if...else statement that we will read in the article on decision making. 

Syntax:

$var = (condition)? value1 : value2;

Here, the condition will either be evaluated as true or false. If the condition evaluates to True, then value1 will be assigned to the variable $var; otherwise, value2 will be assigned to it.

Example: This example describes the Conditional or Ternary operators in PHP.

<?php
  $x = -12;
  echo ($x > 0) ? 'The number is positive' : 'The number is negative';
?>

The number is negative

5. Assignment Operators

Assignment operators are used to assign values to variables. These operators allow you to assign a value and perform operations in a single step.

Example: This example describes the assignment operator in PHP.

<?php
  // Simple assign operator
  $y = 75;
  echo $y, "\n";

  // Add then assign operator
  $y = 100;
  $y += 200;
  echo $y, "\n";

  // Subtract then assign operator
  $y = 70;
  $y -= 10;
  echo $y, "\n";

  // Multiply then assign operator
  $y = 30;
  $y *= 20;
  echo $y, "\n";

  // Divide then assign(quotient) operator
  $y = 100;
  $y /= 5;
  echo $y, "\n";

  // Divide then assign(remainder) operator
  $y = 50;
  $y %= 5;
  echo $y;
?>

75
300
60
600
20
0

6. Array Operators

These operators are used in the case of arrays. Here are the array operators, along with their syntax and operations, that PHP provides for the array operation.

Example: This example describes the array operation in PHP.

<?php
  $x = array("k" => "Car", "l" => "Bike");
  $y = array("a" => "Train", "b" => "Plane");

  var_dump($x + $y);
  var_dump($x == $y) + "\n";
  var_dump($x != $y) + "\n";
  var_dump($x <> $y) + "\n";
  var_dump($x === $y) + "\n";
  var_dump($x !== $y) + "\n";
?>

Output:

array(4) {
  ["k"]=>
  string(3) "Car"
  ["l"]=>
  string(4) "Bike"
  ["a"]=>
  string(5) "Train"
  ["b"]=>
  string(5) "Plane"
}
bool(false)
bool(true)
bool(true)
bool(false)
bool(true)

7. Increment/Decrement Operators

These are called the unary operators as they work on single operands. These are used to increment or decrement values.

Example: This example describes the Increment/Decrement operators in PHP. 

<?php
  $x = 2;
  echo ++$x, " First increments then prints \n";
  echo $x, "\n";

  $x = 2;
  echo $x++, " First prints then increments \n";
  echo $x, "\n";

  $x = 2;
  echo --$x, " First decrements then prints \n";
  echo $x, "\n";

  $x = 2;
  echo $x--, " First prints then decrements \n";
  echo $x;
?>

3 First increments then prints 
3
2 First prints then increments 
3
1 First decrements then prints 
1
2 First prints then decrements 
1

8. String Operators

This operator is used for the concatenation of 2 or more strings using the concatenation operator ('.'). We can also use the concatenating assignment operator ('.=') to append the argument on the right side to the argument on the left side.

Example: This example describes the string operator in PHP.

<?php
  $x = "Geeks";
  $y = "for";
  $z = "Geeks!!!";
  echo $x . $y . $z, "\n";
  $x .= $y . $z;
  echo $x;
?>

GeeksforGeeks!!!
GeeksforGeeks!!!