Java 8 - Predicate VS Function

Predicate :
* To implement condition check and return true or false.
* Predicate<T> - It is can take one input parameter.
* Predicate interface contain test()
* public boolean test(T t)

Function:
* To implement some operation and return some values.
* Function<T,R> - T - Input type, R - Return type.
* Function interface contain apply()
* public R apply(T t)


Program using both:

class Employee
{
String name;
double salary;
Employee(String name,double salary)
{
this.name=name;
this.salary=salary;
}
public String toString()
{
return name+":"+salary;
}
}


class Test
{
public static void main(String[] args)
{
ArrayList<Employee> l= new ArrayList<Employee>();
populate(l);

System.out.println("Before Increment:");
System.out.println(l);

Predicate<Employee> p=e->e.salary<3500;
Function<Employee,Employee> f=e->{
e.salary=e.salary+477;
return e;
};
System.out.println("After Increment:");
ArrayList<Employee> l2= new ArrayList<Employee>();
for(Employee e: l)
{
if(p.test(e))
{
l2.add(f.apply(e));
}
}
System.out.println(l);
System.out.println("Employees with incremented salary:");
System.out.println(l2);
}

public static void populate(ArrayList<Employee> l)
{
l.add(new Employee("Sunny",1000));
l.add(new Employee("Bunny",2000));
l.add(new Employee("Chinny",3000));
l.add(new Employee("Pinny",4000));
l.add(new Employee("Vinny",5000));
l.add(new Employee("Durga",10000));
}
}
Output:
Before Increment: [Sunny:1000.0, Bunny:2000.0, Chinny:3000.0, Pinny:4000.0, Vinny:5000.0, Durga:10000.0] After Increment: [Sunny:1477.0, Bunny:2477.0, Chinny:3477.0, Pinny:4000.0, Vinny:5000.0, Durga:10000.0] Employees with incremented salary: [Sunny:1477.0, Bunny:2477.0, Chinny:3477.0]