在他面前重构他的代码，并显示两个版本之间的差异。他肯定会喜欢的。

这完全取决于你写作的文化。在一个自由软件项目中，你告诉他们他们写的代码不好，并给出积极的建议、改进方法和反馈。你也可以给他们的代码发送一个补丁。

一封友好的电子邮件也不会有什么坏处。

没有人喜欢听别人说他们的工作很糟糕，但任何理智的人都会欢迎指导和避免不必要工作的方法。

有一种教学流派甚至说，你不应该指出错误，而应该专注于做对的事情。例如，与其指出难以理解的代码不好，不如指出他们的代码特别容易阅读的地方。在第一种情况下，你会引导其他人像蹩脚程序员一样思考和行动。在后一种情况下，你会像一个熟练的专业人士一样思考。

人们编写糟糕的代码只是无知的一种症状(这与愚蠢不同)。这里有一些对付这种人的技巧。

Peoples own experience leaves a stronger impression than something you will say. Some people are not passionate about the code they produce and will not listen to anything you say Paired Programming can help share ideas but switch who's driving or they'll just be checking email on their phone Don't drown them with too much, I've found even Continuous Integration needed to be explained a few times to some older devs Get them excited again and they will want to learn. It could be something as simple as programming robots for a day TRUST YOUR TEAM, coding standards and tools that check them at build time are often never read or annoying. Remove Code Ownership, on some projects you will see code silos or ant hills where people say thats my code and you can't change it, this is very bad and you can use paired programming to remove this.

介绍代码标准的思想。关于代码标准最重要的事情是它提出了代码库的一致性(理想情况下，所有的代码都应该看起来像由一个人一次编写的)，这将导致更容易理解和可维护的代码。

糟糕的命名习惯:总是不可原谅的。

是的，不要总是认为你的方式更好……这可能很困难，但必须保持客观性。

I've had an experience with a coder that had such horrible naming of functions, the code was worse than unreadable. The functions lied about what they did, the code was nonsensical. And they were protective/resistant to having someone else change their code. when confronted very politely, they admitted it was poorly named, but wanted to retain their ownership of the code and would go back and fix it up "at a later date." This is in the past now, but how do you deal with a situation where they error is ACKNOWLEDGED, but then protected? This went on for a long time and I had no idea how to break through that barrier.

Global variables: I myself am not THAT fond of global variables, but I know a few otherwise excellent programmers that like them A LOT. So much so that I've come to believe they are not actually all that bad in many situations, as they allow for clarity, ease of debugging. (please don't flame/downvote me :) ) It comes down to, I've seen a lot of very good, effective, bug free code that used global variables (not put in by me!) and great deal of buggy, impossible to read/maintain/fix code that meticulously used proper patterns. Maybe there IS a place (though shrinking perhaps) for global variables? I'm considering rethinking my position based on evidence.