JavaFX

Type inference sometimes doesn't behave like you would expect, so you often need to explicitly declare the type. def behaves likes const in C and not final in Java you can insert a value in a sequence by accessing an index >= seq.length, which should actually throw a compiler error (according to the reference). if you assign null to a String, it defaults to "". If you assign null to an Integer, a compiler error is thrown (in contrast to what the reference says). handles CheckedExceptions the same way as RuntimeExceptions

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。

Python:

处理数字太慢了。这不是什么大问题，除非…… 不能简单地在程序中包含导入时自动编译的C代码。 在py3k接管之前，我们仍然要忍受愚蠢的整数除法规则。 在py3k接管之前，像imap和izip这样的好东西仍然存在于一个单独的模块中。 在py3k接管之前，我们还有很多工作要做。

Python

__init__ 有些库很笨拙，比如smtplib self必须在方法声明中!! (3.0之前)对unicode的支持有点差 缺少内联尝试捕获 没有直接引用"this"/current模块(相反必须使用sys.modules[__name__])

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++

The inconsistencies in the libraries related to char* and std::string. All C++ libs should take std::strings. Characters are not bytes with respect to iostream. I do a lot of byte-oriented work. Having a "byte" type and a "character" type would significantly make it simpler. That, too, would permit scaling to Unicode somewhat easier. Bit operations should be easy on a value. I should be able to access and set the n'th bit of a value without playing AND/OR dancing. The lack of a standardized interface for GUIs. This is where Microsoft has really been able to position themselves well with C#. A standard interface binding that OS makers provide would go really far for my work.