JavaScript:

The Object prototype can be modified. Every single object in your program gets new properties, and something probably breaks. All objects are hash maps, but it's difficult to safely use them as such. In particular, if one of your keys happens to be __proto__, you're in trouble. No object closure at function reference time. In fact, no object closure at all -- instead, this is set whenever a function is called with object notation or the new operator. Results in much confusion, particularly when creating event callbacks, because this isn't set to what the programmer expects. Corollary: calling a function without object notation or the new operator results in this being set equal to the global object, resulting in much breakage. Addition operator overloaded to also perform string concatenation, despite the two operations being fundamentally different. Results in pain when a value you expect to be a number is in fact a string. == and != operators perform type coercion. Comparisons between different types involve a list of rules that no mortal can remember in full. This is mitigated by the existence of === and !== operators. Both null and undefined exist, with subtly different, yet redundant meanings. Why? Weird syntax for setting up prototype chains. parseInt(s) expects a C-style number, so treats values with leading zeroes as octal, etc. You can at least parseInt(s, 10) but the default behaviour is confusing. No block scope. Can declare the same variable more than once. Can use a variable without declaring it, in which case it's global and probably breaks your program. with { }. Really difficult to document with JavaDoc like tools.

C++

Strings. They are not interoperable with platform strings, so you end up using std::vector half of the time. The copy policy (copy on write or deep copy) is not defined, so performance guarantees can not be given for straightforward syntax. Sometimes they rely on STL algorithms that are not very intuitive to use. Too many libraries roll their own which are unfortunately much more comfortable to use. Unless you have to combine them. Variety of string representations Now, this is a little bit of a platform problem - but I still hope it would have been better when a less obstinate standard string class would have been available earlier. The following string representations I use frequently: generic LPCTSTR, LPC(W)STR allocated by CoTaskMemAlloc, BSTR, _bstr _t (w)string, CString, std::vector a roll-my-own class (sigh) that adds range checking and basic operations to a (w)char * buffer of known length Build model. I am sick to death of all the time spent muddling around with who-includes-what, forward declarations, optimizing precompiled headers and includes to keep at least incremental build times bearable, etc. It was great in the eighties, but now? There are so many hurdles to packing up a piece of code so it can be reused that even moms dog gets bored listening to me. Hard to parse This makes external tools especially hard to write, and get right. And today, we C++ guys are lacking mostly in the tool chain. I love my C# reflection and delegates but I can live without them. Without great refactoring, I can't. Threading is too hard Language doesn't even recognize it (by now), and the freedoms of the compiler - while great - are to painful. Static and on-demand initialization Technically, I cheat here: this is another puzzle piece in the "wrap up code for reuse": It's a nightmare to get something initialized only when it is needed. The best solution to all other redist problems is throwing everything into headers, this problem says "neeener - you cannot".

诚然，其中许多内容超出了严格的语言范围，但在我看来，整个工具链都需要进行判断和发展。

ColdFusion

大型Flash表单的编译时间。 动态变量类型(有时我讨厌它们) CFScript缺乏特性。 CFTable(永远不能正确显示)。 CFChart中缺少图表类型。 完全缺乏NTLM支持(企业就绪-是的) cfc中的低能变量作用域 没有一个真正的NULL的概念-你的变量只是消失! 没有办法测试某些东西的存在(比如作用域，只是它们内部的成员)

Python:

No standard GUI toolkit (the community goes round and round about this but never seems to settle on anything). The evolution of tools and methods to distribute and install Python apps and libraries has been, well, rocky. (Although lately this seems to be moving closer to getting fixed.) CPython is still slow as interpreters go (although PyPy is looking pretty good these days, if it becomes the "standard" Python this problem goes away). You can't subclass built-in classes (e.g., list and dict) without overriding a lot of methods, even if all you want to do is a simple hook into an event (e.g., to hook into an item being added to or removed from the list, you need to override delitem, append, extend, insert, pop, and remove--there's no subclassable "change" event notification, nor any "protected" methods that factor out common code used by all the above methods). Up until virtualenv was invented, keeping separate Python environments for different purposes on one machine was a real pain.

Python:

1) It's a scripting language and not a fully compiled one (I'd prefer to be able to compile binaries—I don't care about bytecode). This is very annoying if I have to use very many libraries (i.e. everyone who uses my program has to install all the libraries, and this basically means no normal people will be able to, or have the patience to, properly set it up—unless I do a ton of work that should be unnecessary). I know ways to make binaries, but they don't always work, and I'm guessing they bundle the interpreter in the binaries anyhow (and I don't want that). Now, if I could get a bytecode compiler that would include copies of all the files that I imported (and only those) to be placed in my program's folder, that might be a suitable compromise (then no one would have to download extra libraries and such). It would also be nice if the compiled python files could be compressed into a single file with one specified as the file to run the program before this is done.

2)有时看起来有点bug;有几次，应该工作的代码根本没有工作(没有程序员错误)，特别是与“from moduleX import *”和其他导入相关的问题有关的代码，以及一些与全局和局部变量有关的问题。

3)最大递归深度可以更高。至少有一次，我觉得我需要它去更高的地方。

4)没有switch语句(更不用说允许数字、字符串和范围的语句)

5)新版本的Python似乎取消了很多有用的字符串操作，而且似乎没有简单的文档说明如何在没有它们的情况下做同样的事情。

6)强制自动垃圾收集(我希望能够手动执行，尽管不一定强制执行)。

7)没有预先制作的定时器类没有使用GUI(好吧，可能有一个，但在我所做的所有搜索之后，它肯定不方便找到!我确实找到了一些东西，但当我尝试时，它根本不起作用。)所谓计时器，我指的是每隔x秒执行一个指定函数的排序，并能在需要时关闭它，等等。

8)社区里举例的人很少告诉我们他们导入了哪些模块，以及他们是如何导入的。

9)与Lua集成的支持并不多。

10)似乎没有办法向一个类的特定实例(而不是整个类)添加一个额外的函数，除非你动态地向该类添加一个对象变量，该对象具有所需的函数(但仍然，你必须为此创建另一个类)。

VB。网

1)如果不是x是"foo"(而不是<> "foo") 2)“OrElse”和“AndAlso”短路(而不是简单的“Or”和“and”，它们的作用不同) 3) Nothing(而不是Null)