Expressions and functions in scala

In this post , let us learn about the expressions and functions in scala

Expressions

Expressions are the one which gets evaluated  in scala . We have different operators to achieve this .Will look at those below .

Mathematical operators:
+ -> Addition
– -> Subtraction
* -> Multiplication
/ -> Division
& -> bitwise AND
| -> bitwise OR
^ -> bitwise exclusive OR
<< -> bitwise left shift
>> -> bitwise right shift
>>> -> right shift with zero extension only in scala

Relational operators:
== -> Equal to
!= -> not equal to
> -> greater than
>= -> greater than or equal to
< -> lesser than
<= -> lesser than or equal to

Boolean operators :
! -> negation(unary operator)
&& -> logical AND(binary operator)
|| -> logical OR(binary operator)

other operators:

+= , -= , *= , /=

Functions

Following is the function used for adding two values .

def – keyword

a and b – parameters

Int – data type (First letter must in capital)

1. Normal function :

def func (a: Int, b: Int ): Int =
  {
    a + b
  }
  println(func(20,10))

30

Its not mandatory to provide return type in the case of normal function . Below is the way I tried without any return type .

def func (a: Int, b: Int ) =
  {
    a + b
  }
  println(func(20,10))

30

2. Function without parameter

Function can also be without any parameter as like below .

// invoking with parenthesis   
def func1 () : Int =42
   println(func1())

42

Other way to invoke parameterless function in scala is the below option.

// invoking without parenthesis
def func1 () : Int =42
   println(func1)

42

3.Recursive function

A function gets called continuously by itself .

def func1(a: String ,b: Int) : String = {
    if (b==1)  a
    else a + (func1("Success",b-1))
  }
  println(func1("Success", 5))

SuccessSuccessSuccessSuccessSuccess

We must specify the return type for this .

def func1(a: String ,b: Int) = {
    if (b==1)  a
    else a + (func1("Success",b-1))
  }
  println(func1("Success", 5))

identifier expected but '=' found.
    def func1(a: String ,b: Int) :  = {