Basics

Comments

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Types

Type	Description	Range
Byte	8 bit signed value	-128 to 127
Short	16 bit signed value	-32768 to 32767
Int	32 bit signed value	-2147483648 to 2147483647
BitInt	Very big integer signed value
Long	64 bit signed value	-9223372036854775808 to 9223372036854775807
Float	32 bit IEEE 754 single-precision float	-3.4028235E38 to 3.4028235E38
Double	64 bit IEEE 754 double-precision float	-1.7976931348623157E308to 1.7976931348623157E308
BitDecimal	Very big floatingpoint value
Char	16 bit unsigned Unicode character	U+0000 to U+FFFF
String	A sequence of Chars
Boolean	Either the literal true or the literal false	true, false
Unit	Corresponds to no value
Null	null or empty reference

Array

Fixed length array

val favNums = new Array[Int](20)

val friends = Array("Bob", "Alice")
friends(0) = "Maja"

ArrayBuffer

Array of undefined length

val friends = ArrayBuffer[String]()
friends.insert(0, "Maja")
friends += "Katja"

friends ++= Array("Bob", "Alice")

friends.insert(2, "Maja", "Katja")

friends.remove(2,3)

Operators

In all examples

var a = 10
var b = 20

Arithmetic

Operator	Description	Example
+	Adds two operands	a + b => 30
-	Subtracts second operand from the first	a - b => -10
*	Multiplies both operands	a * b => 200
/	Divides numerator by the de-numerator	b / a => 2
%	Modulus operator finds the remainer after division of one number by another	b % a => 0

Relational

Operator	Description	Example
==	Checks if values if two operands are equal	a == b => false
!=	Checks if values of two operands are not equal	a != b => true
>	Checks if left operands is greater than the right	a > b => false
<	Checks if left operands is less than the right	a < b => true
>=	Checks if left operands is greater or equal than the right	a >= b => false
<=	Checks if left operands is less or equal than the right	a <= b => true

Logical

Operator	Description	Example
&&	It is called Logical AND operator	(a && b) => false
||	It is called Logical OR Operator	(a || b) => true
!	It is called Logical NOT Operator	!(a && b) => true

Bitwise

Performs bit by bit operation

Operator	Description	Example
&	Binary AND Operator copies a bit to the result if it exists in both operands.	(a & b) => 0000 1100 = 12
|	Binary OR Operator copies a bit if it exists in either operand.	(a | b) => 0011 1101 = 61
^	Binary XOR Operator copies the bit if it is set in one operand but not both.	(a ^ b) => 0011 0001 = 49
~	Binary Ones Complement Operator is unary and has the effect of 'flipping' bits.	(~a) => 1100 0011 = -61
<<	Binary Left Shift Operator. The bit positions of the left operands value is moved left by the number of bits specified by the right operand.	a << 2 => 1111 0000 = 240
>>	Binary Right Shift Operator. The Bit positions of the left operand value is moved right by the number of bits specified by the right operand.	a >> 2 => 1111 = 15
>>>	Shift right zero fill operator. The left operands value is moved right by the number of bits specified by the right operand and shifted values are filled up with zeros.	a >>> 2 => 0000 1111 = 15

Assignments

Operator	Description	Example
=	Simple assignment operator, Assigns values from right side operands to left side operand	c = a + b
+=	Add AND assignment operator, It adds right operand to the left operand and assign the result to left operand	c += a
-=	Subtract AND assignment operator, It subtracts right from the left and assign the result to left operand	c -= a
*=	Multiply AND assignment operator, It multiplies right with the left and assign the result to left operand	c *= a
/=	Divide AND assignment operator, It divides left operand with the right operand and assign the result to left	c /= a
%=	Modulus AND assignment operator, It takes modulus using two operands and assign the result to left operand	c %= a
<<=	Left shift AND assignment operator	c <<= a
>>=	Right shift AND assignment operator	c >>= a
&=	Bitwise AND assignment operator	c &= a
^=	Bitwise exclusive OR and assignment operator	c ^= a
|=	Bitwise inclusive OR and assignment operator	c |= a

Operator Priority

Category	Operator	Associativity
Postfix	() []	Left to right
Unary	! ~	Right to right
Multiplicative	* / %	Left to right
Additive	+ -	Left to right
Shift	>> >>> <<	Left to right
Relational	> >= < <=	Left to right
Equality	== !=	Left to right
Bitwise AND	&	Left to right
Bitwise XOR	^	Left to right
Bitwise OR	|	Left to right
Logical AND	&&	Left to right
Logical OR	||	Left to right
Assignment	= += -= *= /= %= >>= <<= &= ^= |=	Right to right
Comma	,	Left to right