Javascript's Round vs PHP's Round

22 Jun 2016 Today I learned that by default PHP rounds differently than javascript.

PHP (using the default PHP_ROUND_HALF_UP)

php > echo round(-1.5);
-2

"Round val up to precision decimal places away from zero, when it is half way there. Making 1.5 into 2 and -1.5 into -2."

https://secure.php.net/manual/en/function.round.php

Javascript

Math.round(-1.5);
-1

"For negative numbers, if the decimal portion is exactly -0.5, the return value is the smallest integer that is greater than the number."
https://msdn.microsoft.com/en-us/library/5cza0web(v=vs.94).aspx