In Java terms, symbols are interned strings. This means, for example, that reference equality comparison (eq in Scala and == in Java) gives the same result as normal equality comparison (== in Scala and equals in Java): ‘abcd eq ‘abcd will return true, while “abcd” eq “abcd” might not, depending on JVM’s whims (well, it … Read more
The := notation serves both as a declaration and as initialization. foo := “bar” is equivalent to var foo = “bar” Why not using only foo = “bar” like in any scripting language, you may ask ? Well, that’s to avoid typos. foo = “bar” fooo = “baz” + foo + “baz” // Oops, is … Read more
It provides a static (compile time) check that boolType satisfies the ValueConverter interface. The _ used as a name of the variable tells the compiler to effectively discard the RHS value, but to type-check it and evaluate it if it has any side effects, but the anonymous variable per se doesn’t take any process space. … Read more
You can do it like this: let p = new Person (Name = “John”, BirthDate = DateTime.Now)
You seem to have stumbled upon the answer. Anyway, I’ll try to make it clear. You can omit dot when using the prefix, infix and postfix notations — the so called operator notation. While using the operator notation, and only then, you can omit the parenthesis if there is less than two parameters passed to … Read more
As the markdown documentation states, it is fine to use HTML if you need a feature that is not part of Markdown. HTML5 supports <mark>Marked text</mark> Else you can use span as suggested by Rad Lexus <span style=”background-color: #FFFF00″>Marked text</span>
The * operator is known as the Spread Operator in Kotlin. From the Kotlin Reference… When we call a vararg-function, we can pass arguments one-by-one, e.g. asList(1, 2, 3), or, if we already have an array and want to pass its contents to the function, we use the spread operator (prefix the array with *): … Read more
In PowerShell V2, @ is also the Splat operator. PS> # First use it to create a hashtable of parameters: PS> $params = @{path = “c:\temp”; Recurse= $true} PS> # Then use it to SPLAT the parameters – which is to say to expand a hash table PS> # into a set of command line … Read more
Update: Since M11 (0.11.*) Kotlin supports secondary constructors. For now Kotlin supports only primary constructors (secondary constructors may be supported later). Most use cases for secondary constructors are solved by one of the techniques below: Technique 1. (solves your case) Define a factory method next to your class fun C(s: String) = C(s.length) class C(a: … Read more
TL; DR In summary, syntax is the concept that concerns itself only whether or not the sentence is valid for the grammar of the language. Semantics is about whether or not the sentence has a valid meaning. Long answer: Syntax is about the structure or the grammar of the language. It answers the question: how … Read more