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Which is better, return value or out parameter?
...od with an out parameter, if I had the choice. C# 7's Deconstruct methods for language-supported deconstruction acts as a very, very rare exception to this rule.)
Aside from anything else, it stops the caller from having to declare the variable separately:
int foo;
GetValue(out foo);
vs
int foo...
SBT stop run without exiting
...you can't easily kill them separately.
If you do your run in a separate, forked JVM, as described at Forking, then you can kill that JVM (by any means your operating system offers) without affecting sbt's JVM:
fork in run := true
...
Run a callback only if an attribute has changed in Rails
...
Rails 5.1+
class Page < ActiveRecord::Base
before_save :do_something, if: :will_save_change_to_status_id?
private
def do_something
# ...
end
end
The commit that changed ActiveRecord::Dirty is here: https://github.com/rails/rails/commit/16ae3d...
WPF Data Binding and Validation Rules Best Practices
...eate custom ValidationRules, but I am wondering if this would be overkill for my needs.
6 Answers
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Scheduling recurring task in Android
...g task of sending presence to a dedicated server as long as the app is in foreground.
5 Answers
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Why is exception.printStackTrace() considered bad practice?
...tem.err PrintStream. The System.err stream and the underlying standard "error" output stream of the JVM process can be redirected by
invoking System.setErr() which changes the destination pointed to by System.err.
or by redirecting the process' error output stream. The error output stream may be r...
What do < and > stand for?
I know that the entities &lt; and &gt; are used for < and > , but I am curious what these names stand for.
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When to throw an exception?
I have exceptions created for every condition that my application does not expect. UserNameNotValidException , PasswordNotCorrectException etc.
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How to check if an app is installed from a web-page on an iPhone?
...ant to create a web-page, a page that will redirect an iPhone to the app-store if the iPhone does not have the application installed, but if the iPhone has the app installed I want it to open the application.
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What's a quick way to test to see a file exists?
...o quickly check to see if a file exists in my iPhone app's Documents directory (or any path for that matter). I can enumerate through the directory's files, or I can try to open a specific file. What's the fastest way? I just need to know if the file is there or if it does not exist.
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