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Safe (bounds-checked) array lookup in Swift, through optional bindings?
...er, I've happened to stumble on a nicer way of implementing this functionality:
Swift 3.2 and newer
extension Collection {
/// Returns the element at the specified index if it is within bounds, otherwise nil.
subscript (safe index: Index) -> Element? {
return indices.contains(i...
Calculate a Running Total in SQL Server
...em is that the SQL Server implementation of the Over clause is somewhat limited.
Oracle (and ANSI-SQL) allow you to do things like:
SELECT somedate, somevalue,
SUM(somevalue) OVER(ORDER BY somedate
ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
AS RunningTotal
FROM Table...
if a ngSrc path resolves to a 404, is there a way to fallback to a default?
...age is the center-piece of the application, so the broken image link makes it look like the whole thing is borked. I'd like to have another image take its place on a 404.
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How do you fork your own repository on GitHub?
I have a public repository on GitHub. I want to replicate/copy it and work on a new project based on this repository, but I don't want to affect how it is now. I tried forking it using the GitHub UI but it didn't do anything.
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Should we @Override an interface's method implementation?
Should a method that implements an interface method be annotated with @Override ?
15 Answers
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Seeking clarification on apparent contradictions regarding weakly typed languages
... the 15th of October, 2012. Thanks for the great question!
What does it really mean for a language to be "weakly typed"?
It means "this language uses a type system that I find distasteful". A "strongly typed" language by contrast is a language with a type system that I find pleasant.
The t...
Understanding the Rails Authenticity Token
I am running into some issues regarding the Authenticity Token in Rails, as I have many times now.
10 Answers
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Why does PHP 5.2+ disallow abstract static class methods?
...w a load of strict standards warnings from a project that was originally written without strict warnings:
8 Answers
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How are strings passed in .NET?
...
A reference is passed; however, it's not technically passed by reference. This is a subtle, but very important distinction. Consider the following code:
void DoSomething(string strLocal)
{
strLocal = "local";
}
void Main()
{
string strMain = "main";...
What are the differences between type() and isinstance()?
... the contents of other (already good!) answers, isinstance caters for inheritance (an instance of a derived class is an instance of a base class, too), while checking for equality of type does not (it demands identity of types and rejects instances of subtypes, AKA subclasses).
Normally, in Python,...