PHP ArithmeticError

The ArithmeticError class is inherited from the Error class. This type of error occurs while performing certain mathematical operations. One such scenario is attempting to perform a bitwise shift operation by a negative amount. This error is also thrown when a call to the intdiv() function results in a value that is beyond the legitimate boundaries of an integer.

Bitwise Shift with Negative Number

In the following example, an attempt is made to use the binary shift operator with a negative operand. This results in an ArithmeticError ?

<?php
try {
    $a = 10;
    $b = -3;
    $result = $a << $b;
}
catch (ArithmeticError $e) {
    echo $e->getMessage();
}
?>

Bit shift by negative number

Integer Division Overflow

If a call to the intdiv() function results in an invalid integer, ArithmeticError is thrown. As shown in the example below, the minimum allowed integer in PHP (PHP_INT_MIN) cannot be divided by -1 ?

<?php
try {
    $a = PHP_INT_MIN;
    $b = -1;
    $result = intdiv($a, $b);
    echo $result;
}
catch (ArithmeticError $e) {
    echo $e->getMessage();
}
?>

Division of PHP_INT_MIN by -1 is not an integer

Common Scenarios

ArithmeticError typically occurs in these situations:

• Bitwise left or right shift by negative numbers
• Integer division overflow with intdiv()
• Operations that exceed integer boundaries

Conclusion

ArithmeticError helps catch mathematical operations that would produce invalid results. Always use try-catch blocks when performing operations that might exceed integer limits or involve negative shift operations.