PHP Operator Precedence

Operator precedence in PHP determines the order in which operations are evaluated in expressions. Understanding precedence helps you write correct code and avoid unexpected results. For example, in 2+6/3, division happens first (resulting in 2+2=4) because the division operator / has higher precedence than addition +.

How Precedence Works

When operators have the same precedence level, associativity (left-to-right or right-to-left) determines the evaluation order. You can override precedence using parentheses to force specific operations to execute first −

<?php
// Without parentheses - multiplication first
echo 2 + 3 * 4; // Result: 14 (2 + 12)
echo "<br>";

// With parentheses - addition first  
echo (2 + 3) * 4; // Result: 20 (5 * 4)
?>

14
20

PHP Operator Precedence Table

The following table lists PHP operators in decreasing order of precedence (highest to lowest) −

Common Precedence Examples

Here are practical examples showing how precedence affects expression evaluation −

<?php
// Arithmetic precedence
echo 10 + 5 * 2; // 20 (not 30)
echo "<br>";

// Logical precedence  
$a = true;
$b = false;
echo $a && $b || $a; // 1 (true)
echo "<br>";

// Assignment vs comparison
$x = 5;
$result = $x = 10; // Assignment has lower precedence
echo $result; // 10
?>

20
1
10

Conclusion

Understanding PHP operator precedence is crucial for writing predictable code. When in doubt, use parentheses to explicitly control the order of operations and make your code more readable.