在SQL Server中，如果你在生产代码中使用select *，你可能会遇到一个令人讨厌的意外。无论如何，使用select *并不被认为是一个好的实践，但了解一些有趣的行为是很好的。

参见问题“select * from table”vs“select colA,colB etc from table”在SqlServer2005中有趣的行为了解更多细节

我有点纠结:

1;

在perl中，模块需要返回true。

PHP对字符串中数值的处理。详见之前对另一个问题的回答，但简而言之:

"01a4" != "001a4"

如果你有两个包含不同数量字符的字符串，它们不能被认为是相等的。前导零很重要，因为它们是字符串而不是数字。

"01e4" == "001e4"

PHP doesn’t like strings. It’s looking for any excuse it can find to treat your values as numbers. Change the hexadecimal characters in those strings slightly and suddenly PHP decides that these aren’t strings any more, they are numbers in scientific notation (PHP doesn’t care that you used quotes) and they are equivalent because leading zeros are ignored for numbers. To reinforce this point you will find that PHP also evaluates "01e4" == "10000" as true because these are numbers with equivalent values. This is documented behaviour, it’s just not very sensible.

INTERCAL可能是最奇怪的语言特征的最佳汇编。我个人最喜欢的是COMEFROM语句，它(几乎)与GOTO相反。

COMEFROM is roughly the opposite of GOTO in that it can take the execution state from any arbitrary point in code to a COMEFROM statement. The point in code where the state transfer happens is usually given as a parameter to COMEFROM. Whether the transfer happens before or after the instruction at the specified transfer point depends on the language used. Depending on the language used, multiple COMEFROMs referencing the same departure point may be invalid, be non-deterministic, be executed in some sort of defined priority, or even induce parallel or otherwise concurrent execution as seen in Threaded Intercal. A simple example of a "COMEFROM x" statement is a label x (which does not need to be physically located anywhere near its corresponding COMEFROM) that acts as a "trap door". When code execution reaches the label, control gets passed to the statement following the COMEFROM. The effect of this is primarily to make debugging (and understanding the control flow of the program) extremely difficult, since there is no indication near the label that control will mysteriously jump to another point of the program.

这并不是一个奇怪的特性，但从类型安全的角度来看，它确实令人恼火:c#中的数组协方差。

class Foo { }
class Bar : Foo { }
class Baz : Foo { }

Foo[] foo = new Bar[1];
foo[0] = new Baz(); // Oh snap!

我相信这是从Java继承而来的(双关语)。

Perl的CORE::开放和标准库具有面向对象的元素，用一个过程性接口掩盖: Open (my $fh， '>'， 'foobar'); Open是一个构造函数，对my()返回的引用进行操作，并接受参数'>'和'foobar'。此外，这是一个受祝福的typeglob对象(意味着它不能在对象内部保存状态)。

关于我的perlmonks post IO::File vs CORE::的更多信息，请在这里打开:http://www.perlmonks.org/?node_id=763565