In functional programming, functions are assigned to variables, passed to other functions as parameters, and returned as values from other functions. Such functions are called as First Class Functions.
Use case 1:
Assign function as Variable
scala>(i:Int) => {i*2}
scala>val doubler = (i:Int) => {i*2}
scala>doubler(5)
Use case 2:
Pass function as Parameter
scala>def operation(functionparam:(Int, Int) => Int){
println(functionparam(10,5))
}
scala> val sum = (x:Int, y:Int)=> x+y
scala>operation(sum);
scala>val diff = (x:Int, y:Int)=> x-y
scala>operation(diff);
Use case 3:
Return a Function
object prwatech {
def main(args: Array[String]) {
val doubleValue = doubler();
print("Double of 2 = " + doubleValue(2));
}
def doubler() = (num: Int) => num * 2;
}
Output
Double of 2 = 4
