Higher-order functions are functions that take other functions as arguments or return functions as their results.

1. In the below example we Search employee by Location using Predicate.
2. If we are not using HOF we need to assign new predicate to variable each and everytime like empFromDelhi
3. Instead of doing that we have a HOF getEmpByLocation which takes location as string in arguments and returns function in its return type

public class HigherOrdFns {
    public static void main(String[] args) {
        Employee objEmp1 = new Employee(101, "Mugil", 30, "Chennai", "600018", 5, 5000);
        Employee objEmp2 = new Employee(102, "Mani", 33, "Chennai", "600028", 4, 6000);
        Employee objEmp3 = new Employee(103, "Madhu", 32, "Chennai", "600054", 6, 10000);
        Employee objEmp4 = new Employee(104, "Vinu", 29, "Bangalore", "500234", 5, 15000);
        Employee objEmp5 = new Employee(105, "Srini", 40, "Delhi", "622142", 10, 7000);
        Employee objEmp6 = new Employee(106, "Dimple", 35, "Delhi", "622142", 5, 8000);

        List<Employee> arrEmployee = Arrays.asList(objEmp1, objEmp2, objEmp3, objEmp4, objEmp5, objEmp6);

        Predicate<Employee> empFromDelhi = employee -> employee.getLocation().equals("Delhi");

        arrEmployee.stream().filter(empFromDelhi).forEach(System.out::println);
        arrEmployee.stream().filter(getEmpByLocation("Chennai")).forEach(System.out::println);
        arrEmployee.stream().filter(getEmpByLocation("Bangalore")).forEach(System.out::println);
    }

    //Higher Order function which return function as return type
    private static Predicate<Employee> getEmpByLocation(String location) {
        return employee -> employee.getLocation().equals(location);
    }
}