F#

Type inference is limited. It propagates forward only. F# won't try to infer an object type based on the methods and properties used: you'll get "lookup of indeterminate object type" errors when it doesn't have a clue. One cannot mix floats and ints: 1 + 2.3 is a type error. It's a little awkward to have to create a builder object in order to define a monad or computation expression. In Haskell or Scala, you can define the monad operations directly on the monadic object. Though the #light syntax is preferred, the indentation rules are sometimes not very intuitive or become cumbersome.

我自己最讨厌c++的5个地方:

自动生成构造函数、析构函数和赋值操作符。伙计，每当我在课上没有声明什么东西时，这意味着我不需要它，而不是我忘记了。你们这些编辑们，听到了吗?!

[4]模板语法。哦，我真的需要输入所有这些“<”和“>”，每当我决定从类主体提取定义?

[3]字符串。天啊，我受够了“const char*”，我必须处理NULL情况，我必须浪费O(N)来获得它的长度，我必须为concat操作分配缓冲区。

[2] Macroprocessing。每当我不明白，什么是我的编译器，我开始寻找宏。

[1]操作符重载。我看到代码“A + B * C”，在我看到A、B和C的实际类型之前，我说不出这个代码是关于什么的。

第一个帖子，所以对我放松点:)…很棒的社区网站，顺便说一句!

我试着阅读其他所有的c#回复，这样我的回复就不会重叠了

c#……排名不分先后:

1) switch语句中的case没有fallthrough。如果没有转机……为什么必须显式的类型中断;呢?这只是弱智和令人困惑，因为它意味着没有休息的能力;!!

2)不能在子作用域中声明同名变量，但可以声明与类变量同名的变量?要么都允许，要么都不允许。否则，就没有意义了。

3)函数中没有可选/默认参数

4) finally{}中的异常应该隐式地捕捉每一行。或者至少，只有NullReferenceException异常。例如，在访问数据库后，应该总是清理。所以，finally块应该看起来像这样:

finally
{
  if(par1 != null)
    par1.Dispose();
  if(comm != null)
    comm.Dispose();
  if(conn != null)
    conn.Dispose();
}

如果可以写成这样，就会简洁得多:

finally
{
    par1.Dispose();
    comm.Dispose();
    conn.Dispose();
}

但是，不……你必须检查你是否正在访问一个空对象，否则它可能会从finally块抛出一个NullReferenceException。谁真的需要finally块中的异常呢?

5)泛型:你可以指定new()来实例化你的泛型对象，但是这个对象需要有一个默认构造函数。为什么不能指定一个签名，这样就不需要在还没有空构造函数的情况下创建空构造函数，而只使用已有的构造函数。

Haskell

Sometimes the type system feels backwards. What if I don't want the compiler to infer types for my variables? What if I want the opposite, where it does constraint checking on said variables? For example, instead of inferring the type of the elements of a list, it instead makes sure that they all belong to a particular typeclass. This is a subtle but huge difference that makes it difficult for me to program UIs. It can be done, but it takes more effort than it does in some other languages. Haskell rocks for the non-UI parts, but the UI I leave to an untyped language. Allowing the construction of infinite values leads to some really frustrating errors sometimes. NoMonomorphismRestriction. Bytestring handling bites me in the ass sometimes and you don't know it until your program crashes because you mixed them up improperly. Something is wrong here, when we are losing type information that should have prevented this. Typeclasses should be automatically derived for trivial cases, like witness types, but there's a strong potential for abuse there.

C#

Lack of multiple dispatch based on the runtime type of the method arguments. dynamic should solve most of this, but it hasn't been released yet. Interface implementation is declarative not structural. I really like the way Google's Go language is doing types Making asynchronous method calls is really bulky (and I'm pretty sure all threads are OS threads, not lightweight threads) No macro system. I'm not talking about C-style macros here; I'm talking LISP/Scheme style macros Operators are static methods and their signatures are overly constrained (and you can't create new ones).

Objective-C / Cocoa / Cocoa Touch:

Lack of namespaces Difficulty using primitive values with any of the interesting and powerful techniques of Cocoa, e.g., distributed objects, notifications, KVO Inconsistency with the use of the shortcut dot syntax for accessing properties, often having to use the full length accessors No GC on the iPhone, and generally GC came rather late to an otherwise highly dynamic language Inconsistent library support, at least in Cocoa Touch; some very basic things have only recently gotten high level support, e.g., audio handling. Lack of blocks!