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How to map and remove nil values in Ruby
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Ruby 2.7+
There is now!
Ruby 2.7 is introducing filter_map for this exact purpose. It's idiomatic and performant, and I'd expect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your ...
Can I set an opacity only to the background image of a div?
...e: linear-gradient(rgba(255,255,255,0.5), rgba(255,255,255,0.5)), url("your_image.png");
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How to get body of a POST in php?
...dy of a POST or PUT request (or any other HTTP method):
$entityBody = file_get_contents('php://input');
Also, the STDIN constant is an already-open stream to php://input, so you can alternatively do:
$entityBody = stream_get_contents(STDIN);
From the PHP manual entry on I/O streamsdocs:
ph...
C# properties: how to use custom set property without private field?
...s for the property's get and set accessors.
See more here
private string _name;
public string Name
{
get => _name;
set
{
DoSomething();
_name = value;
}
}
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How does C compute sin() and other math functions?
...r than the fsin assembly instruction. Source code: sysdeps/ieee754/dbl-64/s_sin.c, look for __sin (double x).
This code is very complex. No one software algorithm is as fast as possible and also accurate over the whole range of x values, so the library implements several different algorithms, and i...
Renaming columns in pandas
...e the name of the first variable of df. Then you can do something like: new_columns = df.columns.values; new_columns[0] = 'XX'; df.columns = new_columns
– cd98
Nov 20 '13 at 14:18
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Save ArrayList to SharedPreferences
... list to preference
SharedPreferences prefs = getSharedPreferences(SHARED_PREFS_FILE, Context.MODE_PRIVATE);
Editor editor = prefs.edit();
try {
editor.putString(TASKS, ObjectSerializer.serialize(currentTasks));
} catch (IOException e) {
e.printStackTrace();
}
editor.commit();
}
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How do I perform a Perl substitution on a string while keeping the original?
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I was wondering if something like my $new = $_ for $old =~ s/foo/bar; would work?
– Benoit
Apr 30 '14 at 17:11
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Calculating Distance between two Latitude and Longitude GeoCoordinates
...tic UnitOfLength Miles = new UnitOfLength(1);
private readonly double _fromMilesFactor;
private UnitOfLength(double fromMilesFactor)
{
_fromMilesFactor = fromMilesFactor;
}
public double ConvertFromMiles(double input)
{
return input*_fromMilesFactor;
}
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PostgreSQL: How to pass parameters from command line?
...and then refer to the variables in sql as :v1, :v2 etc
select * from table_1 where id = :v1;
Please pay attention on how we pass string/date value using two quotes " '...' "
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