PHP Operators - PHP Tutorial

Arithmetic

+ - * / % **

Assignment

PHP

<?php
  $x = 10;
  $x += 5;   // 15  (same as $x = $x + 5)
  $x -= 3;   // 12
  $x *= 2;   // 24
  $x /= 4;   // 6
  $x %= 4;   // 2
  $s = "a";
  $s .= "b"; // "ab" — string append

Comparison

Operator	Meaning
`==`	equal (after type juggling)
`===`	identical (same value and type)
`!=` / `<>`	not equal
`!==`	not identical
`<` `>` `<=` `>=`	ordering
`<=>`	spaceship: returns -1, 0, or 1

PHP

<?php
  var_dump(1 <=> 2); // -1
  var_dump(2 <=> 2); //  0
  var_dump(3 <=> 2); //  1

The spaceship operator exists mainly to make sort callbacks short:

PHP

<?php
  usort($books, fn($a, $b) => $a['price'] <=> $b['price']);

Logical

PHP

<?php
  $a = true; $b = false;

  var_dump($a && $b); // false — and
  var_dump($a || $b); // true  — or
  var_dump(!$a);      // false — not

and/or also exist but have lower precedence than =, which causes subtle bugs. Always use && and ||.

Increment / decrement

PHP

<?php
  $i = 5;
  echo $i++; // prints 5, then $i becomes 6  (post-increment)
  echo ++$i; // $i becomes 7, then prints 7  (pre-increment)

Null-safe operators

PHP

<?php
  // ?? — use the right side if the left is null or undefined
  $name = $_GET['name'] ?? 'Guest';

  // ??= — assign only if currently null
  $config['limit'] ??= 20;

  // ?-> — call a method only if the object isn't null (PHP 8+)
  $city = $user?->address?->city;

?? is the single most useful modern PHP operator — it replaces a pile of isset() checks.

Ternary

PHP

<?php
  $status = $age >= 18 ? "adult" : "minor";