C#

Reference types are nullable by default; in-language null keyword is untyped. Lack of discriminated unions Exceptions as default, non-exceptional error handling method - there's not much of an alternative. archaic switch statement syntax and limitations Needless distinction between constructors + static methods Static methods can't be part of an interface Lack of by-shape interface implementation rather than explicit interface implementation - leading to numerous language design hacks such as the linq query syntax, foreach, collection & object initializers -- none of which can be flexibly reused. For example, the object initializer syntax may be nice, but plays poorly with immutable objects. Cannot inherit "interface" of a class independently of implementation - leading to code duplications and overarchitected code that provides interfaces, abstract base classes, a few common implementations, and no way to pick and choose the bits of each to use. Also; leads to too many code that's tightly coupled to a particular implementation since it's common to explicitly refer to the implementation type rather than an interface. Cannot multiply inherit via composition since a classes "interface" is tightly coupled to it's implementation; effectively lack of mixins. The above limitations of interfaces lead to a proliferation of virtually identical interfaces that don't overlap naturally in any kind of type hierarchy. IComparable vs. IEquatable vs. IComparable<T> vs object.Equals vs. operator == etc. etc. By extension, making a custom type that satisfies all these things is a lot more work than necessary (in particular for collection classes). Obviously, the language designers realize this, hence the various workarounds for things like linq, foreach and collection initializers which work by-shape rather than by-interface. Redundant use of parentheses and braces rather than layout-is-structure. Return values can be ignored, limiting the effectiveness of type inference. Enums aren't a normal type and can't have methods. Also, enum values aren't typesafe and may be initialized to 0 despite not having a 0 value. Mixing metaphors by lumping flag and non-flag enums together. Lack of proper value type support. Value types can't be inherited, have different constructor semantics, and perform poorly due to CLR limitations. Also, confusing semantics regarding value types: some values are really values (and can't be modified), and others are really non-aliased, non-null references (variables). This gets particularly confusing with regards to the next issue: Semantic distinction between fields and properties, particularly in conjunction with lack of mutability modifier (ala C++'s const) Can't specialize generics Cannot provide default generic type parameters (e.g. factory generics) lack of typedef makes generics a pain to use (using is a limited but good-to-know substitute!) Can't genericize over things other than types (e.g. functions, plain values, or names). This means you can't do something like make a generic implementation of a dependancy property leading to, well, nasty implementations of things like dependancy properties and the overuse of code-snippets and poorly readable code as a result. Limited capability to specify generic type requirements e.g. generic sum method that takes both int, double and a bigint (without tricky and often slow hacks). An interface method implementation or virtual method override cannot return a more specific type or accept a more general type; i.e. limited co/contravariance support even in C# 4.

我讨厌Java的五个方面:

没有一级函数。 没有类型推断。 缺乏理智的默认值在eg图形。 NullPointerException不包含更多关于什么是null的信息。 毫无意义的“可配置”框架/服务提供者接口/工厂类/依赖注入系统的激增。可配置性几乎从未使用过，严重违反了DRY，代码的大小增加了四倍，易读性减少了一半。

我知道，我应该试试Scala。

C#

当被枚举的集合中的对象发生变化时，foreach命令弹出， UI控件吐出假人，因为它们在错误的线程上访问。当然是所有的调度员。调用可以移动到CLR管道， PInvoke，编组等， 我浪费了两年时间学习远程遥控， 它没有露比性感。

c#(好吧，我猜一部分是VisualStudio IDE):

No covariance (yet), like Class<D> cannot be used in place of Class<B> even though type D derives from type B. Graphic designers don't support generic based inheritance (or inheritance from abstract classes), even though the inheritance itself works just fine if you work around the designer problems by adding extra inheritance levels just so designers always see concrete non-generic variants of your code. No constructor inheritance No constructors in where clauses of generic type parameters VisualStudio seems to have a tendency to mysteriously check out files (like project files and/or unit test definitions) when opening a solution, even though the files do not seem to actually get altered.

如果你明天再问我，可能会有不同的名单。即使协方差和设计师的麻烦将在我的前5名，直到他们被解决(随着方差添加到c# 4.0，这似乎已经发生了至少一个…)

Lua

我喜欢用Lua编程，但下面是让我头疼的事情:

没有办法用这种语言编写API——不像C .h文件或Java接口 语言有一流的功能，但有人忘记告诉设计库的人。 编写函数的语法太重量级了。 语法分为语句和表达式。 表达式形式是贫乏的:没有let形式，没有真正的条件表达式，……

尽管如此，我还是坚持认为Lua非常棒:-)

Scala是我最喜欢的语言。五件讨厌的事?容易:

Takes a long time to learn properly. I know you can write Scala as a 'better java'. That is what we used to say about C++ and C too. I agree this is an inevitable consequence of the deep ideas in the language. But still ... Methods vs. Functions: def f(x: Int) = x*x defines a method f, not a function f. Methods are not functions despite a lot of early Scala tutorial material blurring the distinction. The language tries to blur it too because if you supply a method in some places where a function is expected it is accepted. Do we have to have both methods and functions? Yes it is fundamental. But it was initially confusing to me. Composing classes or objects from mixins in the 'cake' pattern is prone to NPE's. e.g. trait X { val host: String; val url = "http://" + host } is a mixin that will NPE on instantiation, or not, depending on its position in the class declaration. The compiler could tell you if it will fail but doesn't. (In 2.7 anyway.) It is hard to diagnose the problem in complex inheritance graphs. Arrays in 2.8 rely on implicits to mesh with the main scala collection types. But implicits are not applied everywhere. An Array can be supplied where a Seq is expected. But an Option[Array] cannot be supplied where an Option[Seq] is expected. I know there are no completely 'right' ways to handle java Arrays. Type erasure. Enough said.