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).

C

It's so flexible and powerful that it's really easy to write really awful, or downright dangerous code (or, if you prefer, "with great power comes great responsibility"). '=' for assignment, and '==' for equality; easy to confuse in 'if' statements. The implementation of a number of fundamental parts of the language are compiler-dependent; e.g. the size of the basic types, order of bits in bitfields, padding and byte order in unions. Bitfields aren't parameterisable (i.e. you can array of ints, but you can't have an array of bits). String handling could be improved.

我可以为Python添加另一个:

给定一个列表l = [l1, l2，…]， ln]，那么repr(l) = [repr(l1)， repr(l2)，…， repr(ln)]，但str(l) != [str(l1)， str(l2)，…， str(ln)] (str(l) = repr(l))。之所以这样做，是因为列表中可能有模糊的条目，如l = ["foo]， [bar，"， "]，["]， str(l)将返回"[foo]， [bar，]，[]"，这“可能会使用户感到困惑”。然而，这使得str不可能仅用于转储数据，因为list杀死了“仅以可读格式转储数据”。Augh !

c# / .net:

Classes should be sealed by default There should be no lock statement - instead, you should have specific locking objects, and there should be methods such as Acquire which return disposable lock tokens. Corollary: there shouldn't be a monitor for every object. GetHashCode() and Equals() shouldn't be in System.Object - not everything's suitable for hashing. Instead, have an IdentityComparer which does the same thing, and keep the IComparer<T>, IComparable<T>, IEqualityComparer<T> and IEquatable<T> interfaces for custom comparisons. Poor support for immutability Poor way of discovering extension methods - it should be a much more conscious decision than just the fact that I'm using a namespace.

这些都是我想出来的，明天问我，我会想出一个不同的5个:)

PHP:

1)强迫我创造不必要的变量:

$parts = explode('|', $string);
$first = $parts[0];

2) lambdas的实现如此蹩脚，它大致相当于使用eval()，而且如此糟糕，我从未使用过它(参见http://www.php.net/create_function)。

3) try/catch系统只能捕获大约80%可能发生的错误。

4) Regex支持和lambda支持一样蹩脚，因为它必须在常规字符串中编写，这使得最难学的编程工具之一变得困难了三倍。PHP应该是一种“简单”的语言吗?

5)没有办法安全地从$_POST中取出东西，而不写两次或构建自己的函数，或使用'@'操作符:

$x = isset($_POST['foo']['bar']) ? $_POST['foo']['bar'] : null;

6)额外答案:“@”。如果你懒得写正确的代码，那就添加'@'，这对以后调试你的代码的人来说太糟糕了。

Haskell:

惰性计算导致空间泄漏。 数字层次结构不是根据数学抽象构造的。 严格的单元IO会使调试更加困难。 大型实现处理I/O的方式似乎与标准不太兼容。(特别是，输出字符只输出低8位——然后构建代码，使用这个假设来执行二进制I/O。我吐!) ($)运算符的结合性可以被改变以使某些表达式更漂亮。

大多数问题都不会上升到讨厌的程度，有些人试图解决或为每一个问题构建可靠的变通办法。

编辑:关于第5点有些困惑。特别是有些人似乎认为我指的是论证的顺序，但我不是。我不解释我的意思，我只想让人们去下面的链接http://hackage.haskell.org/trac/haskell-prime/wiki/ChangeDollarAssociativity，它很好地表达了我的意思。