What do square brackets mean in Scala?
Scala uses square brackets everywhere to refer to types, in some predictable ways, in some rather hairy ways, which hopefully we can avoid. 1 Page 2 The first example is a call to a constructor that takes one type argument and one regular argument.
What is generic function in Scala?
When the generic class is used, the code will specify which type to use in each case. Unlike value parameters, type parameters are rarely more than one letter long, and by convention, they start with the letter A. A two-parameter example would be something like class Bar[A, B].
What is a generic class?
Generic classes encapsulate operations that are not specific to a particular data type. The most common use for generic classes is with collections like linked lists, hash tables, stacks, queues, trees, and so on.
What is difference between function and method in Scala?
Scala functions are first class values. Difference between Scala Functions & Methods: Function is a object which can be stored in a variable. But a method always belongs to a class which has a name, signature bytecode etc. Basically, you can say a method is a function which is a member of some object.
Why Scala does not have checked exception?
The case of Checked Exceptions Scala does not have checked exceptions. The compiler does not enforce exceptions to be handled. For example, the below code which is a direct translation of the above java code block compiles just fine. It will throw an error if there is no such file is present only at the run time.
Can we have try finally without catch?
Yes, we can have try without catch block by using finally block. You can use try with finally. As you know finally block always executes even if you have exception or return statement in try block except in case of System.
How do I pass an argument to a Scala object?
you can access your Scala command-line arguments using the args array, which is made available to you implicitly when you extend App . As an example, your code will look like this: object Foo extends App { if (args. length == 0) { println(“dude, i need at least one parameter”) } val filename = args(0) }
Can functions be declared anywhere in Scala?
A function definition can appear anywhere in a source file and Scala permits nested function definitions, that is, function definitions inside other function definitions. Most important point to note is that Scala function’s name can have characters like +, ++, ~, &,-, –, \, /, :, etc.
Which is a type parameter identifier in Scala?
One convention is to use the letter A as type parameter identifier, though any parameter name may be used. This implementation of a Stack class takes any type A as a parameter. This means the underlying list, var elements: List [A] = Nil, can only store elements of type A.
How is a generic class defined in Scala?
Generic classes are classes which take a type as a parameter. They are particularly useful for collection classes. Defining a generic class. Generic classes take a type as a parameter within square brackets []. One convention is to use the letter A as type parameter identifier, though any parameter name may be used.
Which is an example of a polymorphic method in Scala?
Polymorphic Methods. Methods in Scala can be parameterized by type as well as value. The syntax is similar to that of generic classes. Type parameters are enclosed in square brackets, while value parameters are enclosed in parentheses. Here is an example: The method listOfDuplicates takes a type parameter A and value parameters x and length.
