Let’s say we have number 1 to 100
in a list we will see how to perform different operations on this List in Java
and Scala.
Add numbers 1 to 100 in a list
Java Way of doing it
|
Scala way of doing it
|
public static void main(String[]
args) {
List<Integer> list = new
ArrayList<>();
for(int
i=0;i<=100;i++){
list.add(i);
}
}
|
val numbers = (1 to 100).toList
|
Get the sum of numbers
Java Way of doing it
|
Scala way of doing it
|
int sum = 0;
for (Integer num :
list) {
sum+=num;
}
System.out.println(sum);
|
println(numbers.foldLeft(0)((x,y)=>(x+y)))
|
Get the sum of even numbers
Java Way of doing it
|
Scala way of doing it
|
int sum = 0;
for (Integer num :
list) {
if(num%2==0){
sum+=num;
}
}
System.out.println(sum);
|
println(numbers.filter(_%2==0)
.foldLeft(0)((x,y)=>(x+y)))
|
Get the sum of odd numbers that
are greater than 15
Java Way of doing it
|
Scala way of doing it
|
int sum = 0;
for (Integer num :
list) {
if(num%2==1 && num>15){
sum+=num;
}
}
System.out.println(sum);
|
println(numbers.filter(x=>(x%2==1 && x>15))
.foldLeft(0)((x,y)=>(x+y)))
|
From above examples we can see
that by passing function to a list we can reduce the line of code that we need
to write. This also have an advantage when code is running in multithreaded
environment. I will keep adding similar examples for comparing Java and Scala
in this tutorial.
