PHP:避免被零除的优雅方法 [英] PHP: Elegant way to avoid division by zero

问题描述

很像这个站点，我当前的项目具有声誉，在我正在处理的脚本中，我需要计算两个用户的声誉之间的比率.

Much like this site, my current project has reputation and in the script that I'm working on I need to calculate the ratio between two users' reputations.

$attacker->ratio = $defender->rep / $attacker->rep;
$defender->ratio = $attacker->rep / $defender->rep;

这样做，我有时可能会导致除数的声誉为0，这很糟糕！

In doing so I may occasionally end up with the divisor's reputation being 0, which sucks!

很明显，我可以添加一些检查，但是我想知道是否还没有发明更漂亮的解决方案，例如@ infront，但是我知道这不是一个好主意.

Obviously I can add a couple of checks, but I was wondering if a prettier solution hasn't been invented, something like @ infront, but I know that's not a good idea..

推荐答案

假设正数有效，则确保最小除数为1.

Assuming positive numbers are valid then ensure the lowest divisor value will be 1.

$defender->ratio = $attacker->rep / max($defender->rep, 1);

//--------------------------------------------

// --------------------------------------------

别人建议的代码，

@php_nub_qq建议使用备用代码...
在今天的php

@php_nub_qq suggested alternate code...
In today's php

$defender->ratio = $attacker->rep / ($defender->rep ?? 1);

las，@ php_nub_qq提供的此代码在PHP 7.4中不起作用；-((请参阅注释中的@OceanBt ...感谢他们的纠正！:)

Alas, this code provided by @php_nub_qq does not work in PHP 7.4 ;-( see @OceanBt in the comments... I thank them for the correction! :)

所以，在这里，我正在维护我从未感兴趣的代码.现在，该代码显示为特定于PHP版本的！这是更正...

so, Here I am maintaining code that I never was interested in. And now, is shown to be PHP version specific! Here is the correction...

$ y = 100/($ x?:1);

$y = 100/($x ?: 1);

我为什么要这样做? 1)注意我的代码仍然可以正常工作！避免将聪明的功能"用于生产代码. 2)因为有人认为答案更好"并不意味着他们这样做！

Why am I doing this? 1) Notice my code still works fine! Avoid 'clever features' for production code. 2) Because someone believes that have a 'better answer' doesn't mean they do!

我不介意对其他人的代码进行这种维护！这是真实的世界！我们必须这样做.我发布它的原因是:
我确实在尝试帮助程序员学习.

I don't mind doing this maintainance of the code of someone else! This is the real world! We have to do this. I posted it because:
I really am trying to help programmers to learn.

//我对改进"我发布的内容的想法...

// My thoughts about the 'improvement' to what I posted...

imo，您的建议与我的方法不同！我专门使用了"max"，因为它强制限制数字范围.您可以嵌套最小"和最大"功能，以强制限制范围.

imo, that suggestion of yours isn't the same as my approach! I specifically used 'max' as it forces a limit on a range of numbers. You can nest the 'min' and 'max' functions also to force a limited range.

您的方法是选择"，而不是为什么我回答了我. :)

Your method is a 'selection' and not why I did the answer I did. :)

这篇关于PHP:避免被零除的优雅方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！