C#

泛型参数是不变的，c# 4.0为泛型类型引入了协方差和逆变性 可覆盖的类成员必须显式地标记为virtual

Java

缺少无符号数字数据类型 基本数据类型不是对象

C

字符串操作。

必须手动处理字符串缓冲区是一个容易出错的痛苦。由于如此多的计算实际上是移动和修改字符串(计算机并不像人们想象的那样用于大型数字运算)，因此能够使用托管语言或c++的字符串对象来处理这些非常好。当我必须在直发C时，感觉就像在流沙中游泳。

Python:

Too slow! list operations don't return the list, so you can't do list.append(4).append(5). (I mean a reference to the same list, not a copy). This is a minor gripe; it's only come up a few times. statements don't return values (if, print, while, for, etc). This is only a problem when dealing with lambdas. lambdas can only be one expression. There's no real need for this restriction, as they are equivalent to functions in every other way. What if I want a button press event which calls two functions? I'd need to create a named function to supply that functionality to an action listener, while doing "lambda: f1(); f2()" would not hurt. you can only put standard a-zA-Z_0-9 as names. Having functions like "true?" and "+" would be great. Of course, this could lead to terrible obfuscation, but I'm not saying we immediately rename all functions to "p@$%3". Which do you find clearer to read: "dec2bin" or "dec->bin"? ("store_results" or "storeResults") or "store-results"?

Oracle SQL

DUAL表。 不能通过别名分组。 我永远记不住分析函数的语法，所以我忘记/懒得使用它们。 缺少组合的LIKE和IN条件运算符。(不过，在10g之后，有一个REGEX_LIKE操作符可以做到这一点。) 笨拙的连接语法。

SQL并不是我最喜欢的语言，但它是我每天使用的三大语言之一。可能还有更多的项目，但这些是我脑海中最重要的。

我有一大堆SQL*PLUS的问题。我写了一个Perl的替代品，从命令行做我想做的，我使用sql。Emacs中的el用于交互式SQL会话。这些工具可以帮助我解决SQL*PLUS问题。

说到这里:

Perl

"Only perl can parse Perl." (But this is mostly an issue in syntax highlighting, which I don't prefer to use much anymore for any language.) I'm sometimes surprised by "the simple (but occasionally surprising) rule...: It looks like a function, therefore it is function, and precedence doesn't matter." (From perlfunc(1)) Dereferencing complex data structures can be confusing at times. I can't decide if this is a true flaw in Perl or just a consequence of having really powerful data structure facilities. Either way, I can normally get it right by taking a few minutes to think about what I'm doing. No option to cause system calls to raise their errors like the DBI module. (Thanks to brian d foy, I now know the autodie module on CPAN does this, but I'd like it built-in.) Warnings and strictures not enabled by default in scripts. (The -e option would turn them off for command line use.)

同样，肯定还有更多的事情，但这些是我最近注意到的问题。我还要加上=over and =back和古怪的L<…>语法在POD中，但也许那应该是一个单独的列表。

现在来看看三连冠:

康壳牌

Sourcing a file with arguments replaces the values of the parent script's arguments. (Executing . file arg1 puts arg1 in $1.) ksh is not an ideal interactive shell and defaults to vi key-bindings, rather than emacs. (My solution is to use bash for interactive shells.) Common utilities (such as grep) are implemented differently across different platforms thereby preventing perfect portability. Some useful commands need to be installed on some platforms and are part of the OS core on others. The syntax for conditionals is overly heavy. (if [ ... ]; then ... fi) Although it is Turing Complete, you are eventually going to want to move up to a more expressive language like Perl.

第4个问题的一个解决方案是习惯短路评估:

[ ... ] && ...

Haskell

Sometimes the type system feels backwards. What if I don't want the compiler to infer types for my variables? What if I want the opposite, where it does constraint checking on said variables? For example, instead of inferring the type of the elements of a list, it instead makes sure that they all belong to a particular typeclass. This is a subtle but huge difference that makes it difficult for me to program UIs. It can be done, but it takes more effort than it does in some other languages. Haskell rocks for the non-UI parts, but the UI I leave to an untyped language. Allowing the construction of infinite values leads to some really frustrating errors sometimes. NoMonomorphismRestriction. Bytestring handling bites me in the ass sometimes and you don't know it until your program crashes because you mixed them up improperly. Something is wrong here, when we are losing type information that should have prevented this. Typeclasses should be automatically derived for trivial cases, like witness types, but there's a strong potential for abuse there.

C#

5. 空合并运算符

的? ?运算符允许你写:

x = y ?? z;

而不是:

x = (y == null) ? y : z;

我喜欢这个运算符，但我想要另一个:

x = y ??? y.foo() : z.foo();

而不是

x = (y == null) ? y.foo() : z.foo();

我一直在使用这种东西，而且我发现输入== null部分很烦人。

4. 平等应该有更好的支持

我必须启动每个Equals(object obj)方法: MyClass other = obj作为MyClass; If (other == null)返回false;

你只需要写:

public override bool Equals(MyClass other) {...}

语言应该注意提供Equals(object obj)方法。 注意:other必须保证不为空。

3.不能使用不同类型的三元运算符

这不能编译，我认为它应该编译!

string foo = "hello";
int bar = 4;
object baz = foo == null ? foo : bar;

2. 缺少命名空间private

我喜欢内部保护，但我希望有一种保护只允许从同一名称空间内进行访问。这样可以更好地控制大型类库的访问。

1. 没有多重继承

我实际上只对接口的默认实现使用实现(类)继承，但很多时候我想这样做。