Break statement in Scala

In Scala, we use a break statement to break the execution of the loop in the program. Scala programming language does not contain any concept of break statement(in above 2.8 versions), instead of break statement, it provides a break method, which is used to break the execution of a program or a loop. Break method is used by importing scala.util.control.breaks._ package. Flow Chart: Syntax:

// import package
import scala.util.control._

// create a Breaks object 
val loop = new breaks;

// loop inside breakable
loop.breakable{

// Loop starts
for(..)
{
// code
loop.break
}
}

or

import scala.util.control.Breaks._
breakable 
{
 for(..)
{
 code..
 break
}
}

For example:

Scala

// Scala program to illustrate the
// implementation of break

// Importing break package
import scala.util.control.Breaks._
object MainObject
{

// Main method
def main(args: Array[String])
{

    // Here, breakable is used to prevent exception
    breakable
    {
        for (a <- 1 to 10)
        {
            if (a == 6)

                // terminate the loop when
                // the value of a is equal to 6
                break
            else
             println(a);
        }
    }
}
}

Output:

1
2
3
4
5

Break in Nested loop: We can also use break method in nested loop. For example:

Scala

// Scala program to illustrate the
// implementation of break in nested loop

// Importing break package
import scala.util.control._

object Test
{

// Main method
def main(args: Array[String])
{
    var num1 = 0;
    var num2 = 0;
    val x = List(5, 10, 15);
    val y = List(20, 25, 30);

    val outloop = new Breaks;
    val inloop = new Breaks;

    // Here, breakable is used to
    // prevent from exception
    outloop.breakable
    {
        for (num1 <- x)
        {

            // print list x
            println(" " + num1);

            inloop.breakable
            {
            for (num2 <- y)
            {

            //print list y
            println(" " + num2);

            if (num2 == 25)
            {

            // inloop is break when
            // num2 is equal to 25
            inloop.break;
            }
            }

        // Here, inloop breakable
            }
        }

    // Here, outloop breakable
    }
}
}

Output:

  5
 20
 25
 10
 20
 25
 15
 20
 25

Explanation: In the above example, the initial value of both num1 and num2 is 0. Now first outer for loop start and print 5 from the x list, then the inner for loop start its working and print 20, 25 from the y list, when the controls go to num2 == 25 condition, then the inner loop breaks. Similarly for 10 and 15.