What is the VB.NET select case statement logic with case OR-ing?
Use the comma operator to delimit case statements Select Case 2 Case 0,1,2,3 Console.WriteLine(“hit”) End Select
syntax
What is the difference between = and := in Scala?
= in scala is the actual assignment operator — it does a handful of specific things that for the most part you don’t have control over, such as Giving a val or var a value when it’s created Changing the value of a var Changing the value of a field on a class Making a …
Best way to format multiple ‘or’ conditions in an if statement
I use this kind of pattern often. It’s very compact: Define a constant in your class: private static final Set<Integer> VALUES = Set.of(12, 16, 19); // Pre Java 9 use: VALUES = new HashSet<Integer>(Arrays.asList(12, 16, 19)); In your method: if (VALUES.contains(x)) { … } Set.of() returns a HashSet, which performs very well even for very …
Best syntax for a = (x == null) ? null : x.func()
Well, you could use an extension method like this: public static TResult NullOr<TSource, TResult>(this TSource source, Func<TSource, TResult> func) where TSource : class where TResult : class { return source == null ? null : func(source); } Then: var a = some_long_expression.NullOr(x => x.Method()); Or (depending on your version of C#) var a = some_long_expression.NullOr(Foo.Method); …
What is the difference between != and =! in Java? [duplicate]
The question is just playing with you with confusing spacing. b != b is the usual != (not equals) comparison. On the other hand: b =! b is better written as b = !b which is parsed as: b = (!b) Thus it’s two operators. First invert b. Then assign it back to b. The …
What does “&&” do in this batch file?
& separates commands on a line. && executes this command only if previous command’s errorlevel is 0. || (not used above) executes this command only if previous command’s errorlevel is NOT 0 > output to a file >> append output to a file < input from a file | output of one command into the …
What do the three arrow (“>>>”) signs mean?
You won’t see it in source code, it’s probably documentation. It indicates an interactive session, and things typed into the ‘interpreter’ are marked with this. Output is shown without the arrows. In fact, the python documentation often has a button >>>at the top right of example code to be able to hide the arrows (and …
What does the ampersand (&) before `self` mean in Rust?
This means you’ll be passing in a reference to the object, as opposed to moving the object itself. It’s important to distinguish this because if your function looked like: fn eat(self) { println!(“{} is done eating.”, self.name); } and you tried calling it then using the variable after, you’d get an error object = Foo::new(); …
Invalid Token when using Octal numbers
Try 0o10, may be because of python 3, or pyshell itself. PEP says, octal literals must now be specified with a leading “0o” or “0O” instead of “0”; http://www.python.org/dev/peps/pep-3127/
Are square brackets permitted in URLs?
RFC 3986 states A host identified by an Internet Protocol literal address, version 6 [RFC3513] or later, is distinguished by enclosing the IP literal within square brackets (“[” and “]”). This is the only place where square bracket characters are allowed in the URI syntax. So you should not be seeing such URI’s in the …