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Overriding superclass property with different type in Swift

...properties. Instead you can create an extra variable in the subclass that handles the new class type: class Chassis {} class RacingChassis : Chassis {} class Car { var chassis = Chassis() } class RaceCar: Car { var racingChassis = RacingChassis() override var chassis: Chassis { ...
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How to import module when module name has a '-' dash or hyphen in it?

... postfix: "", imageUploader: { brandingHtml: "Powered by \u003ca href=\"https://imgur.com/\"\u003e\u003csvg class=\"svg-icon\" width=\"50\" height=\"18\" viewBox=\"0 0 50 18\" fill=\"none\" xmlns=\"http://www.w3.org/2000/svg\"\u003e\u003cpath d=\"M46.1709 9....
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How to change the type of a field?

... So simply load the document from the DB, perform the cast (new String(x)) and then save the document again. If you need to do this programmatically and entirely from the shell, you can use the find(...).forEach(function(x) {}) syntax. In response to the second comment below. Change the field ba...
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Difference between Node object and Element object?

I am totally confused between Node object and Element object. document.getElementById() returns Element object while document.getElementsByClassName() returns NodeList object(Collection of Elements or Nodes?) ...
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How should I call 3 functions in order to execute them one after the other?

... In Javascript, there are synchronous and asynchronous functions. Synchronous Functions Most functions in Javascript are synchronous. If you were to call several synchronous functions in a row doSomething(); doSomethingElse(); doSomethingUsefulThisTime(); th...
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Run a single migration file

... Sometimes you need a './' in front of the require path, and it definitely doesn't update the schema_migrations. – Beardo Aug 26 '11 at 15:26 14 ...
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How do I do an OR filter in a Django query?

... answered Apr 11 '09 at 11:43 Andy BakerAndy Baker 19k1111 gold badges4848 silver badges7171 bronze badges ...
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How do you query for “is not null” in Mongo?

...rue}}); This will return all documents with both a key called "IMAGE URL" and a non-null value. db.mycollection.find({"IMAGE URL":{$ne:null}}); Also, according to the docs, $exists currently can't use an index, but $ne can. Edit: Adding some examples due to interest in this answer Given these inse...
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Writing string to a file on a new line every time

... I think the f.write method is better as it can be used in both Python 2 and 3. – Dang Manh Truong Apr 10 '18 at 12:02 add a comment  |  ...
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Where to get “UTF-8” string literal in Java?

... In Java 1.7+, java.nio.charset.StandardCharsets defines constants for Charset including UTF_8. import java.nio.charset.StandardCharsets; ... StandardCharsets.UTF_8.name(); For Android: minSdk 19 ...