Unit is a subtype of scala. There is only one value of type Unit , () , and it is not represented by any object in the underlying runtime system. A method with return type Unit is analogous to a Java method which is declared void .Simply so, what is unit data type in Scala?
Unit is a value type which carries no meaningful information. There is exactly one instance of Unit which can be declared literally like so: () . All functions must return something so sometimes Unit is a useful return type. AnyRef represents reference types. All non-value types are defined as reference types.
Furthermore, what is Scala AnyVal? AnyVal is the root class of all value types, which describe values not implemented as objects in the underlying host system. Value classes are specified in Scala Language Specification, section 12.2.
Beside above, what is a type in Scala?
In the context of Scala, a type class is a family of types that support a known set of behaviours. This could be, for example, the family of types that expose a unique integer identifier. This is implemented through a trait and any number of implicit instances of that trait.
Does Scala have primitive types?
Scala the language does not have explicit primitive types. The compiler handles optimisation, boxing and unboxing to the JVM's primitive types as needed.
What is data type in Java?
Data type specifies the size and type of values that can be stored in an identifier. The Java language is rich in its data types. Data types in Java are classified into two types: Primitive—which include Integer, Character, Boolean, and Floating Point. Non-primitive—which include Classes, Interfaces, and Arrays.Does Scala have null?
null: The reference types such as Objects, and Strings can be nulland the value types such as Int, Double, Long, etc, cannot be null, the null in Scala is analogous to the null in Java.What is a double in Scala?
Double , a 64-bit IEEE-754 floating point number (equivalent to Java's double primitive type) is a subtype of scala. AnyVal. Instances of Double are not represented by an object in the underlying runtime system. There is an implicit conversion from scala.How do you declare an array in Scala?
Array is a special kind of collection in scala. it is a fixed size data structure that stores elements of the same data type. The index of the first element of an array is zero and the last element is the total number of elements minus one.What is singleton object in Scala?
Instead of static keyword Scala has singleton object. A Singleton object is an object which defines a single object of a class. A singleton object provides an entry point to your program execution. If you do not create a singleton object in your program, then your code compile successfully but does not give output.What is Scala case class?
Scala case classes are just regular classes which are immutable by default and decomposable through pattern matching. It uses equal method to compare instance structurally. All the parameters listed in the case class are public and immutable by default.What is a collection in Scala?
Scala Collections are the containers that hold sequenced linear set of items like List, Set, Tuple, Option, Map etc. Collections may be strict or lazy. The memory is not allocated until they are accessed. Collections can be mutable or immutable.What is long in Scala?
In Scala, Long is a 64-bit signed integer, which is equivalent to Java's long primitive type.What does => mean in Scala?
=> is syntactic sugar for creating instances of functions. Recall that every function in scala is an instance of a class. For example, the type Int => String , is equivalent to the type Function1[Int,String] i.e. a function that takes an argument of type Int and returns a String .What are valid members in objects in Scala?
Scala/Objects. In Scala, an object is a named instance with members such as fields and methods. An object and a class that have the same name and which are defined in the same source file are known as companions. Companions has special access control properties, which is covered under Scala/Access modifiers.What keyword does not exist in Scala?
The main method does not return a value. Therefore, its return type is declared as Unit . This is because static members (methods or fields) do not exist in Scala.What is difference between class and object in Scala?
Defining an object in Scala is like defining a class in Java that has only static methods. However, in Scala an object can extend another superclass, implement interfaces, and be passed around as though it were an instance of a class. (So it's like the static methods on a class but better).Which class is the top of Scala hierarchy?
The diagram shows that the type Any is at the top most of the Scala's class hierarchy. If you are coming from Java or . NET, you can think of the Any type as the Object class. In other words, Any is the root type and it has two sub-classes namely AnyVal and AnyRef as per the above diagram.What is Scala operator?
Operators in Scala. An operator is a symbol that represents an operation to be performed with one or more operand. Operators are the foundation of any programming language. Operators allow us to perform different kinds of operations on operands.How do you create an enum in Scala?
In Scala, there is no enum keyword unlike Java or C. Scala provides an Enumeration class which we can extend in order to create our enumerations. Every Enumeration constant represents an object of type Enumeration. Enumeration values are defined as val members of the evaluation.What is lambda expression in Scala?
Lambda Expression in Scala. Lambda Expression refers to an expression that uses an anonymous function instead of variable or value. Lambda expressions are more convenient when we have a simple function to be used in one place.What is type inference in Scala?
Scala has a built-in type inference mechanism which allows the programmer to omit certain type annotations. It is, for instance, often not necessary in Scala to specify the type of a variable, since the compiler can deduce the type from the initialization expression of the variable. 
