Scala-data types and custom functions

type of data

type of data	description
Byte	8-bit signed integer
Short	16-bit signed integer
Int	32-bit signed integer
Long	64-bit signed integer
Float	32-bit single precision floating point
Double	64-bit single-precision floating-point number
Char	16-bit unsigned character
String	Character sequence
Boolean	true or false
Unit	Means no value, equivalent to void in other languages, var s = ()
Null	null or null reference
Nothing	Nothing produced an exception during execution, def s = throw new Exception ("")
Any	Any is a superclass of all other classes
AnyRef	The AnyRef class is the base class of all reference classes in Scala

Declaration of variables and constants

# 变量声明
var s : String = ""
# 常量声明
val s : String = ""

String concatenation

s"Hello ${s}"

Custom function

# 函数定义的时候，可以不写返回值，scala支持类型推导
def 函数名称(参数名称 : 参数类型) : 返回值类型 = {
	函数的实现
}