What are common issues when performing calculations with negative numbers in PHP?

When performing calculations with negative numbers in PHP, one common issue is the incorrect handling of subtraction and multiplication operations. This is because negative numbers are represented differently in PHP compared to positive numbers. To solve this issue, you can use parentheses to explicitly indicate the order of operations and ensure that negative numbers are treated correctly.

// Incorrect calculation with negative numbers
$incorrectResult = -5 * 2; // This will result in -10 instead of the expected -10

// Correct calculation with negative numbers using parentheses
$correctResult = (-5) * 2; // This will correctly result in -10