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

Common Lisp:

关键词往往太啰嗦。 库支持是可怜的。 在希望更严格地处理内存的操作系统中不能很好地工作。 没有与操作系统交互的良好工具。 “循环”功能没有很好地定义，当然看起来也不像Lispy。

数组部分选择不能给你所要求的。

[1]给出一个元素 A[1:2]给出一个元素，而不是[A [1]， A [2]] A[1:3]给出2个元素

我讨厌这样，但可能是因为我大部分时间都在Verilog上工作。

Ruby:

重要的空白。对于解释器，行尾=语句的结束，除非看起来语句应该继续(或者显式转义换行符)。 慢 在线文档不如Python的好(为了辩护，Python的很棒) 我刚才提到慢了吗?

Python:

Global Interpreter Lock - Dealing with this complicates parallel processing. Lambdas functions are a bit clunky. No built-in ordered-dictionary type. Depending on how Python is compiled, it can use either UCS-2 vs UCS-4 for the internal Unicode encoding, many string operators and iterators may have unexpected results for multi-byte characters that exceed the default width. String slicing and iteration depend on the bit width rather than checking and counting characters. (Most other programming languages do similar things as well and have similarly odd behavior with these characters.) There are inconsistencies surrounding GUI frameworks for Python.

Ruby。

Strange scoping rules - variables, constants, and methods each behave differently from each other. The rules change also depending on which keyword you used to create a closure. Or on whether you're in a class, eigenclass, object, module, or module's self. Then there's instance_eval, which changes the rules to a different set of rules. And they change again when a module is "included" or "extended", which themselves do different things to scope. And some sets of rules can't be emulated by metaprogramming, so you have to use eval. Unless you're on ruby 1.9, where all of this is different. Namespacing is basically useless. If you have Foo::File, then the stdlib File is probably broken for all of Foo. require statement is broken. If two files require eachother, the behavior of those files can change dramatically depending on which is loaded first from elsewhere. libraries change APIs dramatically and suddenly, so you have to require specific minor revision numbers of all of your dependencies. For every single ruby application on your system. The rubygems package system overrides "require" rather than putting files in the search path - because why use a system when you can replace it?