PHP:
Rounding numbers
How to:
PHP offers a few ways to round numbers: round(), ceil(), and floor(). Here’s how they work:
echo round(3.14159); // Returns 3
echo round(3.14159, 2); // Returns 3.14
echo ceil(3.14159); // Returns 4, always rounds up
echo floor(3.14159); // Returns 3, always rounds down
Deep Dive
Rounding numbers has been essential in math and computation since ancient times to deal with impractical infinite decimals. In PHP, round() can take a precision parameter and mode, affecting its behavior – PHP_ROUND_HALF_UP, PHP_ROUND_HALF_DOWN, etc., define how it’ll behave when it meets a “.5” scenario. Precision is key in financial applications where rounding might be legally regulated, affecting how round() gets implemented in code.
Alternatives to built-in functions include custom rounding methods or BC Math functions for arbitrary precision arithmetic, which are useful for scenarios needing more control or dealing with very large numbers where native accuracy might falter.
See Also
Explore more in the PHP manual: