Post By: Hanan Mannan
Contact Number: Pak (+92)-321-59-95-634
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Scala Files I/O

Scala is open to make use of any Java objects and java.io.File is one of the objects which can be used in Scala programming to read and write files. Following is an example of writing to a file:

import java.io._

object Test {
   def main(args: Array[String]) {
      val writer = new PrintWriter(new File("test.txt" ))

      writer.write("Hello Scala")
      writer.close()
   }
}

When the above code is compiled and executed, it creates a file with "Hello Scala" content which you can check yourself.

C:/>scalac Test.scala
C:/>scala Test

C:/>

Reading line from Screen:

Sometime you need to read user input from the screen and then proceed for some further processing. Following example shows you how to read input from the screen:

object Test {
   def main(args: Array[String]) {
      print("Please enter your input : " )
      val line = Console.readLine
      
      println("Thanks, you just typed: " + line)
   }
}

When the above code is compiled and executed, it prompts you to enter your input and it continues until you press ENTER key.

C:/>scalac Test.scala
C:/>scala Test
scala Test
Please enter your input : Scala is great
Thanks, you just typed: Scala is great

C:/>

Reading File Content:

Reading from files is really simple. You can use Scala's Source class and its companion object to read files. Following is the example which shows you how to read from "test.txt" file which we created earlier:

import scala.io.Source

object Test {
   def main(args: Array[String]) {
      println("Following is the content read:" )

      Source.fromFile("test.txt" ).foreach{ 
         print 
      }
   }
}

When the above code is compiled and executed, it will read test.txt file and display the content on the screen:

C:/>scalac Test.scala
C:/>scala Test
scala Test
Following is the content read:
Hello Scala

C:/>