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Why are arrays covariant but generics are invariant?
...invariant rules out useful polymorphic programs.
For example, consider writing a function to shuffle an array, or a function that tests two arrays for equality using the Object.equals method on the elements. The implementation does not depend on the exact type of element stored in the array, so it...
How and when to use ‘async’ and ‘await’
From my understanding one of the main things that async and await do is to make code easy to write and read - but is using them equal to spawning background threads to perform long duration logic?
...
How can I break up this long line in Python?
...ow would you go about formatting a long line such as this? I'd like to get it to no more than 80 characters wide:
5 Answers...
Why do Java programmers like to name a variable “clazz”? [closed]
...ant, but abbreviating or inserting junk ("a", "the", "_", etc) reduces clarity. clazz just says class. "International" English speakers (those reading both British and American English) are used to transposing 's' and 'z'.
Since Java has had disclosed source and a suitable culture right from the st...
How to properly override clone method?
...h Bloch on Design - Copy Constructor versus Cloning
If you've read the item about cloning in my book, especially if you read between the lines, you will know that I think clone is deeply broken. [...] It's a shame that Cloneable is broken, but it happens.
You may read more discussion on the to...
Command line to remove an environment variable from the OS level configuration
...e variable from the user environment (which is the default place setx puts it):
REG delete HKCU\Environment /F /V FOOBAR
If the variable is set in the system environment (e.g. if you originally set it with setx /M), as an administrator run:
REG delete "HKLM\SYSTEM\CurrentControlSet\Control\Sessi...
Sleep in JavaScript - delay between actions
Is there a way I can do a sleep in JavaScript before it carries out another action?
11 Answers
...
What are some good Python ORM solutions? [closed]
...e DataMapper pattern). Django ORM has a cleaner syntax and is easier to write for (ActiveRecord pattern). I don't know about performance differences.
SQLAlchemy also has a declarative layer that hides some complexity and gives it a ActiveRecord-style syntax more similar to the Django ORM.
I woul...
Splitting a string into chunks of a certain size
...
static IEnumerable<string> Split(string str, int chunkSize)
{
return Enumerable.Range(0, str.Length / chunkSize)
.Select(i => str.Substring(i * chunkSize, chunkSize));
}
Please note that additional code might be required to gracefully han...
Why is #!/usr/bin/env bash superior to #!/bin/bash?
I've seen in a number of places, including recommendations on this site ( What is the preferred Bash shebang? ), to use #!/usr/bin/env bash in preference to #!/bin/bash . I've even seen one enterprising individual suggest using #!/bin/bash was wrong and bash functionality would be lost by doing...