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Best way to test for a variable's existence in PHP; isset() is clearly broken
... This looks a bit ugly to me, but in the case where you're actually checking an array element, it makes much more sense: isset($foo[$bar]) becomes array_key_exists($bar, $foo)
– Arild
Aug 25 '14 at 14:12
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How do you cast a List of supertypes to a List of subtypes?
...However, you can cast through an intermediate wildcard type and it will be allowed (since you can cast to and from wildcard types, just with an unchecked warning):
List<TestB> variable = (List<TestB>)(List<?>) collectionOfListA;
...
How to specify new GCC path for CMake
... path /usr/bin/gcc . But it is old, I need a new version of gcc. So I install a new version in a new path /usr/local/bin/gcc .
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How do I get around type erasure on Scala? Or, why can't I get the type parameter of my collections?
...hese instances are objects, you can pass them around, store them, and generally call methods on them. With the support of implicit parameters, it becomes a very powerful tool. Take the following example, for instance:
object Registry {
import scala.reflect.Manifest
private var map= Map.empty[...
Adding days to a date in Python
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The previous answers are correct but it's generally a better practice to do:
import datetime
Then you'll have, using datetime.timedelta:
date_1 = datetime.datetime.strptime(start_date, "%m/%d/%y")
end_date = date_1 + datetime.timedelta(days=10)
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How to implement a ConfigurationSection with a ConfigurationElementCollection
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The previous answer is correct but I'll give you all the code as well.
Your app.config should look like this:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="ServicesSection" type="RT.Core.Config.Servic...
Does height and width not apply to span?
...ides no context to indicate that a div is inherently inappropriate semantically.
– Isaac
Mar 22 '10 at 9:45
1
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How to determine a Python variable's type?
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It is so simple. You do it like this.
print(type(variable_name))
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Simultaneously merge multiple data.frames in a list
...ch data.frame differs in terms of the number of rows and columns, but they all share the key variables (which I've called "var1" and "var2" in the code below). If the data.frames were identical in terms of columns, I could merely rbind , for which plyr's rbind.fill would do the job, but that'...
Detect Safari browser
...rAgent);
It uses negative look-arounds and it excludes Chrome, Edge, and all Android browsers that include the Safari name in their user agent.
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