Scala - Data Types

One of the most important parts of learning any programming language is to understand what are the available data types, and how data is stored, accessed and manipulated in that language. Based on the data type of a variable, the operating system allocates memory to the variable and decides what can be stored in the reserved memory.

There are various data types in Scala which can be categorized as below:

Data Types	Description
Boolean	Stores true or false values.
Byte	8-bit signed integer value. It ranges from -128 to 127.
Short	16-bit signed integer value. It ranges -32,768 to 32,767.
Int	32-bit signed integer value. It ranges -2³¹ to 2³¹-1.
Long	64-bit signed integer value. It ranges -2⁶³ to 2⁶³-1.
Float	32-bit IEEE 754 single-precision float. It ranges 1.40129846432481707e-45 to 3.40282346638528860e+38.
Double	64-bit IEEE 754 double-precision float. It ranges 4.94065645841246544e-324d to 1.79769313486231570e+308d.
Char	16-bit unsigned Unicode character. It ranges 0 to 2¹⁶−1.
String	A sequence of Char.
Unit	A value type which carries no meaningful information.
Null	A subtype of all reference types (i.e. any subtype of AnyRef). It has a single value identified by the keyword literal null.
Nothing	A subtype of all types, also called the bottom type. There is no value that has type Nothing.
Any	The supertype of all types, also called the top type. It has two direct subclasses: AnyVal and AnyRef.
AnyRef	Represents reference types. All non-value types are defined as reference types. Every user-defined type is a subtype of AnyRef.

In Scala, specifying a type explicitly is not required. For example: By default 10 will be an Int. If other data type like Byte, Long, or Short is required then it is required to specify the data type as shown below in the given example. Similarly Numbers with a decimal (like 10.0) will be Double by default. If Float data type is required then it is needed to specify the data type as shown in the example below.

As Int and Double are the default numeric types, you typically create them without explicitly declaring the data type.

object MainObject {
  def main(args: Array[String]) {      
    var i: Boolean = true;
    var j: Char = 'A';
    var k: Byte = 10;
    var l: Short = 10;
    var m: Int = 10;
    var n: Long = 10L;
    var o: Float = 10.5f;
    var p: Double = 10.5d; 
    var q: String = "Hello World";

    //printing data types
    println(s"i is a Boolean. i = $i"); 
    println(s"j is a Char. j = $j");
    println(s"k is a Byte. k = $k");
    println(s"l is a Short. l = $l");
    println(s"m is an Int. m = $m");
    println(s"n is a Long. n = $n");
    println(s"o is a Float. o = $o");
    println(s"p is a Double. p = $p");
    println(s"q is a String. q = $q");
  }
}

The output of the above code will be:

i is a Boolean. i = true
j is a Char. j = A
k is a Byte. k = 10
l is a Short. l = 10
m is an Int. m = 10
n is a Long. n = 10
o is a Float. o = 10.5
p is a Double. p = 10.5
q is a String. q = Hello World