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How to check an Android device is HDPI screen or MDPI screen?
...rces().getDisplayMetrics().density;
// return 0.75 if it's LDPI
// return 1.0 if it's MDPI
// return 1.5 if it's HDPI
// return 2.0 if it's XHDPI
// return 3.0 if it's XXHDPI
// return 4.0 if it's XXXHDPI
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How can you do anything useful without mutable state?
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18 Answers
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Active
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Postgresql aggregate array
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163
Use array_agg: http://www.sqlfiddle.com/#!1/5099e/1
SELECT s.name, array_agg(g.Mark) as mark...
javax.xml.bind.UnmarshalException: unexpected element (uri:“”, local:“Group”)
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14 Answers
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Active
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How to add 10 days to current time in Rails
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Use
Time.now + 10.days
or even
10.days.from_now
Both definitely work. Are you sure you're in Rails and not just Ruby?
If you definitely are in Rails, where are you trying to run this from? Note that Active Support has to be loaded.
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How can I unstage my files again after making a local commit?
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git reset --soft HEAD~1 should do what you want. After this, you'll have the first changes in the index (visible with git diff --cached), and your newest changes not staged. git status will then look like this:
# On branch master
# Changes to be ...
Disable Rails SQL logging in console
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321
To turn it off:
old_logger = ActiveRecord::Base.logger
ActiveRecord::Base.logger = nil
To tur...
How to subtract date/time in JavaScript? [duplicate]
...the difference between two dates, in milliseconds
var diff = Math.abs(date1 - date2);
In your example, it'd be
var diff = Math.abs(new Date() - compareDate);
You need to make sure that compareDate is a valid Date object.
Something like this will probably work for you
var diff = Math.abs(new ...
What is Hindley-Milner?
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168
Hindley-Milner is a type system discovered independently by Roger Hindley (who was looking at ...