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Collections.emptyMap() vs new HashMap()
...rrays or collections, not null" demonstrates returning an empty collection and perhaps even demonstrates using these emptyList(), emptySet(), and emptyMap() methods on the Collections class to get an empty collection that also has the additional benefit of being immutable. From Item #15 "Minimize ...
Retrieve specific commit from a remote Git repository
... on my PC? The structure of remote repo is absolutely same as that of mine and hence there won't be any conflicts but I have no idea how to do this and I don't want to clone that huge repository.
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How to detect if multiple keys are pressed at once using JavaScript?
I'm trying to develop a JavaScript game engine and I've came across this problem:
13 Answers
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Panel.Dock Fill ignoring other Panel.Dock setting
If you create a panel on a form and set it to Dock=Top and drop another panel and set its Dock=Fill, it may fill the entire form, ignoring the first panel. Changing the tab order does nothing.
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What does “error: option --single-version-externally-managed not recognized” indicate?
...not recognized when pip install ing varions packages (including PyObjC and astropy ). I've never seen this error before, but it's now also showing up on travis-ci builds for which nothing has changed.
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How to properly create composite primary keys - MYSQL
... gross oversimplification of an intense setup I am working with. table_1 and table_2 both have auto-increment surrogate primary keys as the ID. info is a table that contains information about both table_1 and table_2 .
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What is the difference between Gemfile and Gemfile.lock in Ruby on Rails
I am a beginner to Ruby on Rails and I am using Rails 3.0.9.
3 Answers
3
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Rails extending ActiveRecord::Base
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Create a file in the config/initializers directory called extensions.rb and add the following line to the file:
require "active_record_extension"
Inheritance (Preferred)
Refer to Toby's answer.
Monkey patching (Should be avoided)
Create a file in the config/initializers directory called act...
How to use JavaScript regex over multiple lines?
...to match all newlines, you would need to add \r as well to include Windows and classic Mac OS style line endings: (.|[\r\n]).
That turns out to be somewhat cumbersome, as well as slow, (see KrisWebDev's answer for details), so a better approach would be to match all whitespace characters and all no...
What does “=>” mean in PHP?
...the context of that foreach loop, it assigns the key of the array to $user and the value to $pass.
Example:
$user_list = array(
'dave' => 'apassword',
'steve' => 'secr3t'
);
foreach ($user_list as $user => $pass) {
echo "{$user}'s pass is: {$pass}\n";
}
// Prints:
// "dave's...