大约有 21,000 项符合查询结果（耗时：0.0269秒） [XML]
How to pattern match using regular expression in Scala?
...Regex(sc.parts.mkString, sc.parts.tail.map(_ => "x"): _*)
}
scala> "123" match { case r"\d+" => true case _ => false }
res34: Boolean = true
Even better one can bind regular expression groups:
scala> "123" match { case r"(\d+)$d" => d.toInt case _ => 0 }
res36: Int = 123
sc...
How do I truncate a .NET string?
...
Because performance testing is fun: (using linqpad extension methods)
var val = string.Concat(Enumerable.Range(0, 50).Select(i => i % 10));
foreach(var limit in new[] { 10, 25, 44, 64 })
new Perf<string> {
{ "newstring" + limit, n =&...
Is REST DELETE really idempotent?
...ot all-effects or responses. If you do a DELETE http://example.com/account/123 then the effect is that account 123 is now deleted from the server. That is the one and only effect, the one and only change to the state of the server. Now lets say you do the same DELETE http://example.com/account/123 ...
How can I send large messages with Kafka (over 15MB)?
...rks best only if the messages are huge in amount but not in size.
Source: https://www.quora.com/How-do-I-send-Large-messages-80-MB-in-Kafka
java.util.regex - importance of Pattern.compile()?
...ch is really called a lot :)
public class AmountValidator {
//Accept 123 - 123,456 - 123,345.34
private static final String AMOUNT_REGEX="\\d{1,3}(,\\d{3})*(\\.\\d{1,4})?|\\.\\d{1,4}";
//Compile and save the pattern
private static final Pattern AMOUNT_PATTERN = Pattern.compile(AM...
Why catch and rethrow an exception in C#?
...ple, in VB you can do
Try
..
Catch Ex As MyException When Ex.ErrorCode = 123
..
End Try
...which would not handle MyExceptions with different ErrorCode values. In C# prior to v6, you would have to catch and re-throw the MyException if the ErrorCode was not 123:
try
{
...
}
catch(MyExcepti...
Regular expression to match numbers with or without commas and decimals in text
... are embedded in other text. IMHO anything that fails to pull 1,234.56 and 1234—and only those numbers—out of abc22 1,234.56 9.9.9.9 def 1234 is a wrong answer.
First of all, if you don't need to do this all in one regex, don't. A single regex for two different number formats is hard to maintain...
What is boxing and unboxing and what are the trade offs?
...xing is the conversion of a reference type into a value type.
EX: int i = 123;
object o = i;// Boxing
int j = (int)o;// UnBoxing
Value Types are: int, char and structures, enumerations.
Reference Types are:
Classes,interfaces,arrays,strings and objects
...
How to list only the file names that changed between two commits?
...rex/RexSimplify.java | 50 +++++++++++++++++-----
.../apache/calcite/sql/fun/SqlTrimFunction.java | 2 +-
.../apache/calcite/sql2rel/SqlToRelConverter.java | 16 +++++++
.../org/apache/calcite/util/SaffronProperties.java | 19 ++++----
.../org/apache/calcite/test/RexProgramTest.java | 24 +...
Why doesn't C# support the return of references?
...nks for the great question!
The C# team is considering this for C# 7. See https://github.com/dotnet/roslyn/issues/5233 for details.
UPDATE: The feature made it in to C# 7!
You are correct; .NET does support methods that return managed references to variables. .NET also supports local variables ...