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What does jquery $ actually return?

...et like an array or access individual elements via the indexer ($(sel)[0] for example). More importantly, you can also apply jQuery functions against all the selected elements. About returning nothing: Does it always return an array? Does it return null? You always get the same thi...
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What does this symbol mean in JavaScript?

...r parameter Null-safe property access (and conditional assignment) in ES6/2015 Optional Chaining in JavaScript Is there a null-coalescing (Elvis) operator or safe navigation operator in javascript? Is there a "null coalescing" operator in JavaScript? :: — Double colon: bind operator JavaScri...
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Problems installing the devtools package

... Evan AadEvan Aad 4,90944 gold badges1919 silver badges3131 bronze badges ...
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Get DateTime.Now with milliseconds precision

... 309 How can I exactly construct a time stamp of actual time with milliseconds precision? I sus...
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virtualenv --no-site-packages and pip still finding global packages?

... 108 I had a problem like this, until I realized that (long before I had discovered virtualenv), I ...
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Convert UTC datetime string to local datetime

...o_zone = tz.tzlocal() # utc = datetime.utcnow() utc = datetime.strptime('2011-01-21 02:37:21', '%Y-%m-%d %H:%M:%S') # Tell the datetime object that it's in UTC time zone since # datetime objects are 'naive' by default utc = utc.replace(tzinfo=from_zone) # Convert time zone central = utc.astimezo...
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How to check an Android device is HDPI screen or MDPI screen?

... density = getResources().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 to vertically align an image inside a div

... +550 The only (and the best cross-browser) way as I know is to use an inline-block helper with height: 100% and vertical-align: middle on b...
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The smallest difference between 2 Angles

...his gives a signed angle for any angles: a = targetA - sourceA a = (a + 180) % 360 - 180 Beware in many languages the modulo operation returns a value with the same sign as the dividend (like C, C++, C#, JavaScript, full list here). This requires a custom mod function like so: mod = (a, n) ->...
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How to use HTML Agility pack

...f (htmlDoc.ParseErrors != null && htmlDoc.ParseErrors.Count() > 0) { // Handle any parse errors as required } else { if (htmlDoc.DocumentNode != null) { HtmlAgilityPack.HtmlNode bodyNode = htmlDoc.DocumentNode.SelectSingleNode("//body"); if (bodyNode != null...