Scala Conditional Expressions

Scala provides if statement to test the conditional expressions. It tests boolean conditional expression which can be either true or false. Scala use various types of if else statements.

If statement
If-else statement
Nested if-else statement
If-else-if ladder statement

Scala if statement

The scala if statement is used to test condition in scala. If block executes only when condition is true otherwise execution of if block is skipped.

Syntax

if(condition){
	// Statements to be executed
}

Flowchart

Scala Example: If Statement

var age:Int = 20;
if(age > 18){
    println ("Age is greate than 18")
}

Output:

Age is greate than 18

Scala If-Else Statement

The scala if-else statement tests the condition. If the condition is true, if block executes otherwise else block executes.

Syntax

if(condition){
	// If block statements to be executed
} else {
	// Else bock statements to be executed
}

Flowchart

Scala if-else example

var number:Int = 21
if(number%2==0){
    println("Even number")
}else{
    println("Odd number")
}

Output:

Odd number

Scala If-Else-If Ladder Statement

The scala if-else-if ladder executes one condition among the multiple conditional statements.

Syntax

if (condition1){  
//Code to be executed if condition1 is true  
} else if (condition2){  
//Code to be executed if condition2 is true  
} else if (condition3){  
//Code to be executed if condition3 is true  
}  
...  
else {  
//Code to be executed if all the conditions are false  
}  

Flowchart

Scala If-Else-If Ladder Example

var number:Int = 85
if(number>=0 && number<50){
    println ("fail")
}
else if(number>=50 && number<60){
    println("D Grade")
}
else if(number>=60 && number<70){
    println("C Grade")
}
else if(number>=70 && number<80){
    println("B Grade")
}
else if(number>=80 && number<90){
    println("A Grade")
}
else if(number>=90 && number<=100){
    println("A+ Grade")
}
else println ("Invalid")

Output:

A Grade

Scala If Statement as better alternative of Ternary Operators

In scala, you can assign if statement result to a function. Scala does not have ternary operator concept like C/C++ but provides more powerful if which can return value. Let's see an example

Example

object MainObject {
   def main(args: Array[String]) {
      val result = checkIt(-10)
      println (result)
   }
    def checkIt (a:Int)  =  if (a >= 0) 1 else -1	// Passing a if expression value to function
}

Output: