Scala | Methods to Call Option

The Option in Scala is referred to a carrier of single or no element for a stated type. When a method returns a value which can even be null then Option is utilized i.e, the method defined returns an instance of an Option, in place of returning a single object or a null.
There are a few methods that we can Call on Scala Option.

• def get: A
  This method is utilized to return an Option’s value.
  Example:

  
  

  
  
  

  // Scala program of using // get method    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(20)                // Applying get method         val x = some.get            // Displays the value          println(x)     } }

  Output:

  20
  

  Here, get method cannot be applied to the None class as it will show an exception.

• def productArity: Int
  This method is utilized to return the size of the Option’s value.
  Example:

  
  

  
  
  

  // Scala program of returning  // the size of the value    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(20)                // Applying productArity         // method         val x = some.productArity            // Displays the size of         // the Option's value         println(x)     } }

  Output:

  1
  

• def productElement(n: Int): Any
  This method is utilized to return the n-th element of the stated product and here indexing starts from zero.
  Example:

  
  

  
  
  

  // Scala program of returning  // the n-th element of the // product    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(20)            // Applying productElement         // method         val x = some.productElement(0)            // Displays the element         println(x)     } }

  Output:

  20
  

  Here, None will show an exception.

• def exists(p: (A) => Boolean): Boolean
  When the value of the Option satisfies the stated condition then, this method returns true else returns false.
  Example:

  
  

  
  
  

  // Scala program of the method // 'exists'    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(30)            // Applying exists method         val x = some.exists(y => {y % 3 == 0})            // Displays true if the condition         // given is satisfied else false          println(x)     } }

  Output:

  true
  

  Here, the condition stated is satisfied so, true is returned.

• def filter(p: (A) => Boolean): Option[A]
  This method is utilized to return the value of the Option if the stated condition is satisfied.
  Example:

  
  

  
  
  

  // Scala program of the method // 'filter'    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(30)            // Applying filter method         val x = some.filter(y => {y % 3 == 0})            // Displays the value of the         // option if the predicate          // is satisfied         println(x)     } }

  Output:

  Some(30)
  

  Here, the condition is satisfied so, the Option value is returned and returns None if the predicate is not satisfied.

• def filterNot(p: (A) => Boolean): Option[A]
  This method will return the Option value if the stated condition is not satisfied.
  Example:

  
  

  
  
  

  // Scala program of the method // 'filterNot'    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(30)            // Applying filterNot method         val x = some.filterNot(y => {y % 3 != 0})            // Displays the value of the         // option if the predicate          // is not satisfied         println(x)     } }

  Output:

  Some(30)
  

  Here, the condition is not satisfied so, the Option value is returned and returns None if the predicate is satisfied.

• def isDefined: Boolean
  This method returns true if the Option is an instance of Some and returns false if the Option is an instance of None.
  Example:

  
  

  
  
  

  // Scala program of the method // 'isDefined'    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(30)            // using None class         val none:Option[Int] = None            // Applying isDefined method         val x = some.isDefined         val y = none.isDefined            // Displays true for Some         // and false for None         println(x)         println(y)     } }

  Output:

  true
  false
  

• def iterator: Iterator[A]
  This method returns an iterator on the Option given.
  Example:

  
  

  
  
  

  // Scala program of the method // 'iterator'    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(30)                // Applying iterator method         val x = some.iterator            // Displays an iterator         println(x)     } }

  Output:

  non-empty iterator
  

• def map[B](f: (A) => B): Option[B]
  This method will return the value of the function stated in the Map, if the Option has a value.
  Example:

  
  

  
  
  

  // Scala program of the method // 'map'    // Creating object object GFG {        // Main method     def main(args: Array[String])     {            // Using Some class         val some:Option[Int] = Some(30)            // Applying Map method         val x = some.map(y => {y + y})            // Displays the value returned         // by the function in map         println(x)     } }

  Output:

  Some(60)
  

  These were the methods to call on an Option and there are more such methods.

• def orElse[B >: A](alternative: => Option[B]): Option[B]
  If the Option contain a value, this returns it. Otherwise, this method evaluates the alternative and returns alternative.
   
• def orNull
  This method will return Null, if the Option didn’t contain a value.

nidhi1352singh

Follow

Improve