C#

I wish I could switch() on any type, and that case could be any expression. Can't use object initializer syntax with 'readonly' fields / private set autoprops. Generally, I want language help with making immutable types. Use of {} for namespace and class and method and property/indexer blocks and multi-statement blocks and array initializers. Makes it hard to figure out where you are when they're far apart or mismatched. I hate writing (from x in y ... select).Z(). I don't want to have to fall back to method call syntax because the query syntax is missing something. I want a do clause on query syntax, which is like foreach. But it's not really a query then.

我真的到达这里了。我认为c#非常棒，而且很难发现它有什么缺陷。

Python 3

both tabs & spaces allowed for indentation And you'd think people learn from the past (Makefile). Just pick spaces and forbid tabs. YAML got it right. lack of popular third-party libraries The standard library is great, but a lot of what makes Python 2 so powerful lies in the third-party realm. Python 2 got this right :-). IEEE floats Floating points in programming languages are confusing because they're different from the way we use them in math. Instead, the number operations should be viewed as expressions that are only converted to a decimal point format when needed (i.e. printing to a screen). Maple and Mathematica did this right I think. the character set for identifiers is too restricted list.empty? is better than list.is_empty or even len(list) != 0. Similarly, process.kill! would be better than process.kill. Ruby and lisp got this right. when calling a function you must always write parentheses It would be nice if we could omit them in unambiguous cases. How is it again? dict.items or dict.items()? Ruby got this one right, too.

Python:

Too slow! list operations don't return the list, so you can't do list.append(4).append(5). (I mean a reference to the same list, not a copy). This is a minor gripe; it's only come up a few times. statements don't return values (if, print, while, for, etc). This is only a problem when dealing with lambdas. lambdas can only be one expression. There's no real need for this restriction, as they are equivalent to functions in every other way. What if I want a button press event which calls two functions? I'd need to create a named function to supply that functionality to an action listener, while doing "lambda: f1(); f2()" would not hurt. you can only put standard a-zA-Z_0-9 as names. Having functions like "true?" and "+" would be great. Of course, this could lead to terrible obfuscation, but I'm not saying we immediately rename all functions to "p@$%3". Which do you find clearer to read: "dec2bin" or "dec->bin"? ("store_results" or "storeResults") or "store-results"?

Python。

虽然前面提到了python处理作用域的奇怪方式，但我觉得最糟糕的结果是:

import random

def myFunction():

    if random.choice(True, False):
        myString = "blah blah blah"

    print myString

也就是说，if块内部的作用域与函数的其余部分相同，这意味着变量声明可以出现在条件分支内部，并且可以在条件分支外部访问。大多数语言要么阻止你这样做，要么至少为你提供某种严格的模式。

此函数有时会成功，但有时会抛出异常。虽然这是一个人为的例子，但这可能会导致一些微妙的问题。

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#(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…)