C#

Reference types are nullable by default; in-language null keyword is untyped. Lack of discriminated unions Exceptions as default, non-exceptional error handling method - there's not much of an alternative. archaic switch statement syntax and limitations Needless distinction between constructors + static methods Static methods can't be part of an interface Lack of by-shape interface implementation rather than explicit interface implementation - leading to numerous language design hacks such as the linq query syntax, foreach, collection & object initializers -- none of which can be flexibly reused. For example, the object initializer syntax may be nice, but plays poorly with immutable objects. Cannot inherit "interface" of a class independently of implementation - leading to code duplications and overarchitected code that provides interfaces, abstract base classes, a few common implementations, and no way to pick and choose the bits of each to use. Also; leads to too many code that's tightly coupled to a particular implementation since it's common to explicitly refer to the implementation type rather than an interface. Cannot multiply inherit via composition since a classes "interface" is tightly coupled to it's implementation; effectively lack of mixins. The above limitations of interfaces lead to a proliferation of virtually identical interfaces that don't overlap naturally in any kind of type hierarchy. IComparable vs. IEquatable vs. IComparable<T> vs object.Equals vs. operator == etc. etc. By extension, making a custom type that satisfies all these things is a lot more work than necessary (in particular for collection classes). Obviously, the language designers realize this, hence the various workarounds for things like linq, foreach and collection initializers which work by-shape rather than by-interface. Redundant use of parentheses and braces rather than layout-is-structure. Return values can be ignored, limiting the effectiveness of type inference. Enums aren't a normal type and can't have methods. Also, enum values aren't typesafe and may be initialized to 0 despite not having a 0 value. Mixing metaphors by lumping flag and non-flag enums together. Lack of proper value type support. Value types can't be inherited, have different constructor semantics, and perform poorly due to CLR limitations. Also, confusing semantics regarding value types: some values are really values (and can't be modified), and others are really non-aliased, non-null references (variables). This gets particularly confusing with regards to the next issue: Semantic distinction between fields and properties, particularly in conjunction with lack of mutability modifier (ala C++'s const) Can't specialize generics Cannot provide default generic type parameters (e.g. factory generics) lack of typedef makes generics a pain to use (using is a limited but good-to-know substitute!) Can't genericize over things other than types (e.g. functions, plain values, or names). This means you can't do something like make a generic implementation of a dependancy property leading to, well, nasty implementations of things like dependancy properties and the overuse of code-snippets and poorly readable code as a result. Limited capability to specify generic type requirements e.g. generic sum method that takes both int, double and a bigint (without tricky and often slow hacks). An interface method implementation or virtual method override cannot return a more specific type or accept a more general type; i.e. limited co/contravariance support even in C# 4.

length属性很容易与length()函数混淆;请改用size() 在选择器字符串中插入变量的语法('" +$。Month + "')臭死了 $(event.currentTarget)并不总是适用于冒泡和捕获 属性语法("[class='foot']")在选择器语法(".foot")不返回任何结果的地方起作用 包含选择器([class~=done])有时会在JavaScript (this.className.search("done") > 0)工作时失败

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。

Python

慢 我终于习惯了打印语句，现在有了这个打印函数??(py3k) 从来没有得到py2exe或cxFreeze工作 不标准化(轻微挑剔) 递归深度只有100 (iirc)

C#

我的大部分抱怨都与假设c++约定自动成为c#的最佳选择有关

Class接口中不允许静态。这仍然是课程的一部分。为什么它不能成为界面的一部分?我不得不想出这么愚蠢的变通办法。 区分大小写。我知道在这一点上它会破坏遗留的应用程序，但为什么不区分大小写不是一开始的规则

对于。net的好处之一(不是c#特有的)

编译器不够聪明。在。net 3中。X，编译器可以找出“var”在编译时，为什么不其他常见的优化?我们都知道string和StringBuilder / immutable和mutable的区别。为什么编译器不为你转换它在很多情况下，显然StringBuilder比多个connect .s更好?我相信在默认情况下，编译器可以为我们做大量的其他优化(带有否决选项)，并为我们节省大量的时间。

D

we have in operator, but no !in operator? dynamic array 'length' property - ya canna do array.length += 512; no exit statement - as in python's sys.exit(), etc. Sure, you can call C's exit, but unflushed output don't get flushed associative array literals + string literals suck string literals found as is inside an associative array literal are interpreted as static, thus this char[][char[]] hash = ["hello":"world","goodbye":"angels"]; doesn't work without some extra casting due to different length string literals despite a. I didn't ask it to be interpreted as static arrays b. static arrays aren't allowed in associative arrays anyways cyclic dependencies disallowed (want to port that java lib? Have fun redesigning the class hierarchy)

谁帮我检查一下;不确定它们是否都有意义。