C#

No easy way to check if a type is Numeric It means you are probably stuck using most of the microsoft stack, IIS and MSSQL Instead of being a specific tool for a specific problem, C# tries to be a language for every paradigm. Lack of community. Sure, there are starting to be open-source frameworks and libraries for C#. The same ones that have been available to Java developers for years. Hard to find good help. The internet is littered with poor examples of how to solve problems with C#. This goes back to problem #3.

Perl 5:

All the really good stuff nowadays seems to require mod_perl, which has low availability everywhere I want to go. Some really incredible functionality can be encapsulated in modules, but what is under the hood is often fragile or frightening: source filters, typeglobs, whatever Moose is doing... DateTime is brilliant but still made some very bad design decisions (not returning a stopwatch duration when subtracting two DateTime objects) Dual-lifed modules in core and on CPAN still cause conflicts module authors still put interactive stuff in their module configuration scripts so that they can't be automatically installed

我使用Java，我最大的不满是字符串操作的低效率。当你使用+运算符时。说真的，难道编译器不能计算出我添加了多少字符串，然后在后台为我生成StringBuffer的东西吗?

通常，使用+的代码比StringBuffers操作序列更具可读性。

另外，我讨厌本机数组和集合框架之间的冗余。. toarray()的语法极其丑陋。

我刚刚发现，在c#中创建泛型方法时，我不能使用Enum作为类型约束。

微软有一个足够好的解释，但仍然。我疯了

public static T MyFunc<T>(string arg) where T:Enum //wont work :(

Perl

我喜欢这门语言，我不想添加已经被使用过的东西，但还没有人提到过这一点，所以我就把它扔到锅上。当我使用这个特性时，我发现这是我一生中最可怕的经历(而且我用过汇编语言):

write()和format()函数。

它们的语法是最糟糕、最丑陋、最可怕的，但是它们并没有提供比printf()更好的功能更多的功能。任何人都不应该尝试使用这两个函数进行任何输出，因为它们有多糟糕。

我相信有人会不同意，但是当我研究它们，希望它们能解决我的问题时，我发现它们是一个“痛苦的世界”(引用Big Lebowski的话)，我希望Perl6已经消除了它们，或者更好的是完全重写它们，使它们在某种程度上更可用和有用。

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.