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java.util.regex - importance of Pattern.compile()?
What is the importance of Pattern.compile() method?
Why do I need to compile the regex string before getting the Matcher object?
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How to listen for changes to a MongoDB collection?
I'm creating a sort of background job queue system with MongoDB as the data store. How can I "listen" for inserts to a MongoDB collection before spawning workers to process the job? Do I need to poll every few seconds to see if there are any changes from last time, or is there a way my script can wa...
django templates: include and extends
...lude statement in that child template, you have to put it within a block, for Django to make sense of it. Otherwise it just doesn't make sense and Django doesn't know what to do with it.
The Django documentation has a few really good examples of using blocks to replace blocks in the parent templat...
I lose my data when the container exits
Despite Docker's Interactive tutorial and faq I lose my data when the container exits.
11 Answers
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How to detect Windows 64-bit platform with .NET?
...# application I use the following code to detect the operating system platform:
29 Answers
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What is the purpose of “return await” in C#?
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There is one sneaky case when return in normal method and return await in async method behave differently: when combined with using (or, more generally, any return await in a try block).
Consider these two versions of a method:
Task<SomeResult> DoSomethingAs...
Spring Boot - inject map from application.yml
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You can have a map injected using @ConfigurationProperties:
import java.util.HashMap;
import java.util.Map;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.context.properties.Config...
String concatenation in Ruby
I am looking for a more elegant way of concatenating strings in Ruby.
16 Answers
16
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Why are variables “i” and “j” used for counters?
... ultimately from mathematics: the summation notation traditionally uses i for the first index, j for the second, and so on. Example (from http://en.wikipedia.org/wiki/Summation):
It's also used that way for collections of things, like if you have a bunch of variables x1, x2, ... xn, then an ...
Waiting on a list of Future
...hem throws an exception cancel the processing. Something like this:
Executor executor = Executors.newFixedThreadPool(4);
CompletionService<SomeResult> completionService =
new ExecutorCompletionService<SomeResult>(executor);
//4 tasks
for(int i = 0; i < 4; i++) {
completio...