OMG用这个非常基本的代码找不到我的问题

Question

为了上帝的爱，有人可以帮我弄清楚为什么这个最基本的代码无法在PHP中运行吗？已经使用PHP多年了，但从未见过...在我使用sandbox.onlinephpfunctions.com网站进行测试时，在每个版本的php上都是一致的，请参见代码段下面的链接。

<?php

$lside = 490.84;
$rside = 237.80 + 222.00 + 31.04;

if( $lside == $rside ){
   echo "they are equal\n";
} else {
   echo "not equal\n";
   echo "rside: [$rside]\n";
   echo "lside: [$lside]\n";
}

http://sandbox.onlinephpfunctions.com/code/6dee3a97f68a11e67fbaa8e5c157b827ecd47740

帮助和感谢！

Answer 1

您可以尝试这个：

if( bccomp($lside, $rside, 2) == 0 ){
   echo "they are equal\n";
} else {
   echo "not equal\n";
   echo "rside: [$rside]\n";
   echo "lside: [$lside]\n";
}

因为比较浮点数时比较复杂，所以您可以阅读更多here，而对于bccomp功能则可以阅读更多here

Answer 2

尝试一下

$lside = 490.84;
$rside = 237.80 + 31.04 + 222;
$newRside = number_format($rside,2);

if( $lside == $newRside ){
   echo "they are equal\n";
} else {
   echo "not equal\n";
   echo "rside: [$rside]\n";
   echo "lside: [$lside]\n";
}

Answer 3

您的答案在这里Compare floats in php阅读此页https://www.php.net/manual/en/language.types.float.php