C#

No easy way to check if a type is Numeric It means you are probably stuck using most of the microsoft stack, IIS and MSSQL Instead of being a specific tool for a specific problem, C# tries to be a language for every paradigm. Lack of community. Sure, there are starting to be open-source frameworks and libraries for C#. The same ones that have been available to Java developers for years. Hard to find good help. The internet is littered with poor examples of how to solve problems with C#. This goes back to problem #3.

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.

Java:

很不一致。 图形api有时使用起来很痛苦 nullpointerexception不会告诉你什么是null 我写的程序有时不能在不同的JVM上运行，这是一个巨大的痛苦，与Java的“一次编写，随处运行”语句相矛盾。 Swing并没有达到应有的效果。

C#

我对c#非常满意，但这两个真的让我很恼火:

Constructor-based initialization for immutable classes is less convenient, less intuitive (when you read the code you don't understand what you assign to what), has less IDE backing than inline object initialization. This makes you lean towards mutable classes inevitably. I know this has been mentioned before, but I strictly have problems with initialization syntax for immutable classes. switch is too verbose. Whenever I see a situation where a switch would be proper, I'm really inclined to use an if..else if.. just because it's more terse (~30% less typing). I think there should be no fallthrough for switch, break should be implied, and case should allow comma separated list of values.

Python

Standard library disobeys their own style guidelines in many places. (PEP-8) Py3k's super keyword is full of unwanted magic (you can't assign it to a different name, works without self, why do we have this explicit parameter at all?) Unicode support is incomplete in Py2k and sucks in Py3k (standard input in unicode, no binary data! WTF? Creating a new WSGI standard is hacky.) The GIL. Very limited multi-threading support (with CPython) PyPI (Python Package Index) sucks. Envious glance at rubygems

JavaScript

ECMAScript 5规范:

7.6.1.2未来保留词: 类，enum, extends, super, const, export， 进口 严格模式:实现、let、private、public、interface、package、protected、static、yield 11.9.4严格等于操作符(===)对比11.9.1 TheEqualsOperator(==) 11.9.6严格相等比较算法(NaN === NaN is false) 8.5数字类型-没有实整数，所有都是浮点数。 4.2.1对象——原型继承

好吧，我有点喜欢最后一个，但它有7种让人困惑的地方