Scala (/ˈskɑːlɑː/ SKAH-lah) is a strong statically typed general-purpose programming language which supports both object-oriented programming and functional programming. Designed to be concise, many of Scala’s design decisions are aimed to address criticisms of Java.

Sample program in Scala

object HelloWorld {
	def main(args: Array[String]): Unit = {
	println("Hello, World!")
	}
}

object : Object is a instance of a class. In Scala, everything is considered as objects.
def : def is used for function declaration
main : entry point of the program
println : prints data to the console.
// : Single line comment
/* Multi
Line
comment */

Data types in Scala

Data type	Description	Range	Size
int	used to store whole numbers	-2,147,483,648 to 2,147,483,647	4 bytes
short	used to store whole numbers	-32,768 to 32,767	2 bytes
long	used to store whole numbers	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	8 bytes
byte	used to store whole numbers	-128 to 127	1 byte
float	used to store fractional numbers	6 to 7 decimal digits	4 bytes
double	used to store fractional numbers	15 decimal digits	8 bytes
boolean	can either store true or false	either true or false	1 bit
char	used to store a single character	one character	2 bytes
string	used to store strings	sequence of characters	2bytes per character

Variables in Scala

var varName = value
val  varName = value
varName = value
var varName : DataType = value

Operators in Scala

Type	Operators
Arithmetic Operators	+ , – , * , / , %
Comparision Operators	== , != , > , >= , < , <=
Bitwise Operators	& , ^ , \| , ^ , ~ , << , >> , >>>
Logical Operators	&& , \|\| , !
Assignment Operators	= , += , -= , *= , /= , %= , &= , ^= , \|= , <<= , >>=

Conditional Statements

1. If

if(conditional-expression)
{
    //code
}

2. If-else

if(conditional-expression)
{
    //code
} else {
    //code
}

3. If-else-if ladder

if(conditional-expression-1)
{
    //code
} else if(conditional-expression-2) {
    //code
} else if(conditional-expression-3) {
    //code
}
....
else {
    //code
}

Loops

1. For

for(var <- range){  
//code  
}

2. For loop Using until

for( var <- initialValue until maxValue ){  
    //code  
}

3. For loop filtering

for( var <- initialValue until maxValue if condition){  
  //code
}

4. For loop for collections like lists, sequence etc

for( varName <- Collections){             
  //code
}

5. While

while(condition){  
//code 
}

6. Do-while

do{  
//code 
}while(condition);

Arrays in Scala

Array is a collection of similar data which is stored in continuous memory addresses.

Declaring 1-D array

var arrayName:Array[datatype] = new Array[datatype](size)

//or

var arrayName = new Array[datatype](size)

Declaring 2-D array

var arrName = ofDim[datatype](rowsize,colSize)

Example

 var arr1 = Array(1, 2, 3, 4, 5)

Functions in Scala

How to declare a Function

def functionName ([argumentsList]) : [return type]

How to define a Function

def functionName ([argumentsList]) : [return type] [=] {
   // code
   return [expr]
}

How to call a Function

function_name (argumentsList)

If you have quires and suggestions put them in the comments.

cheatsheet Scala Cheatsheet

Scala Cheatsheet