PHP ROUND vs Javascript ROUND

Question

I found a very strange issue, the issue is the ROUND method in PHP and Javascript the calculation results are not the same!?

See the following example:

PHP

Answer 1

To control it more use ceil and floor for rounding. That way you can choose which way to round

Answer 2

console.log(Math.round(175.5)); // 176
console.log(Math.round(-175.5)); // -175 <-why not -176!!??

175.5 its round value 176 it's value increasing.

-175.5 round value is -175. Because when I round -175.5 then it also increasing that means -175>-176.

Answer 3

That's not an issue, it is well documented

If the fractional portion is exactly 0.5, the argument is rounded to the next integer in the direction of +∞. Note that this differs from many languages' round() functions, which often round this case to the next integer away from zero, instead (giving a different result in the case of negative numbers with a fractional part of exactly 0.5).

If you want the same behaviour on Javascript, I would use

var n = -175.5;
var round = Math.round(Math.abs(n))*(-1)

Answer 4

Or... if you wanted JavaScript to behave the same as PHP, use this:

function phpRound(number) {
  if(number < 0)
    return 0 - Math.round(0 - number);
  return Math.round(number);
}

Answer 5

A quick solution is to do the following:

echo round(-175.5, 0, PHP_ROUND_HALF_DOWN); // -175

There are other modes to choose from:

1. PHP_ROUND_HALF_UP - default
2. PHP_ROUND_HALF_EVEN
3. PHP_ROUND_HALF_ODD

See the documentation for more information.

This function will behave the same as in javascript:

function jsround($float, $precision = 0){
  if($float < 0){
     return round($float, $precision, PHP_ROUND_HALF_DOWN);
  }

  return round($float, $precision);
}