PHP ROUND对比Javascript ROUND [英] PHP ROUND vs Javascript ROUND

问题描述

我发现了一个很奇怪的问题，问题是PHP和Javascript中的ROUND方法的计算结果不一样！?

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

请参见以下示例:

PHP

echo round(175.5); // 176
echo round(-175.5); // -176

JavaScript

Javascript

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

有人知道为什么吗?以及如何使Javascript和PHP具有相同的结果?

anyone know why? and how to make Javascript and PHP the same results?

推荐答案

这不是问题，很好

如果小数部分正好是0.5，则将参数舍入为在+∞方向上的下一个整数.请注意，这与许多语言的round()函数，通常会将这种情况四舍五入到下一个远离零的整数，而不是(在小数部分正好为0.5的负数的情况.

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).

如果您希望在Javascript上具有相同的行为，我会使用

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

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

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