JavaScript

Every script is executed in a single global 'namespace'...something which you have to look out for when working with scripts from different sources If a variable is used but hasnt been defined before hand, it is considered a global variable Browser vendors making up standards as they please, making coding for us developers using such a beautiful language harder than it should be Case-Sensitivity - considering that there is no decent IDE for developing js with compile-time checking Workarounds (such as the use of hasOwnProperty method) to perform some, otherwise simple operations.

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.

Python

没有Django for Python 3。 静态类型。是的，动态类型是很棒的东西，但有时我确实想让它成为静态的。 正确的unicode支持(在Python 3中修复) Construtors命名。我讨厌代码中的所有这些下划线。 线程的效率不是很高

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

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).

Objective-C / Cocoa / Cocoa Touch:

Lack of namespaces Difficulty using primitive values with any of the interesting and powerful techniques of Cocoa, e.g., distributed objects, notifications, KVO Inconsistency with the use of the shortcut dot syntax for accessing properties, often having to use the full length accessors No GC on the iPhone, and generally GC came rather late to an otherwise highly dynamic language Inconsistent library support, at least in Cocoa Touch; some very basic things have only recently gotten high level support, e.g., audio handling. Lack of blocks!