What is the Java equivalent for Enumerable.Select with lambdas in C#?
C#JavaJava 8C# Problem Overview
Say I have an object in C#:
public class Person
{
public string Name{get;set;}
public int Age{get;set;}
}
To select the names from this list in C# I would do the following:
List<string> names = person.Select(x=>x.Name).ToList();
How would I do the same thing in Java 8?
C# Solutions
Solution 1 - C#
If you have a list of Persons like List<Person> persons;
you can say
List<String> names
=persons.stream().map(x->x.getName()).collect(Collectors.toList());
or, alternatively
List<String> names
=persons.stream().map(Person::getName).collect(Collectors.toList());
But collecting into a List
or other Collection
is intented to be used with legacy APIs only where you need such a Collection
. Otherwise you would proceed using the stream’s operations as you can do everything you could do with a Collection
and a lot more without the need for an intermediate storage of the String
s, e.g.
persons.stream().map(Person::getName).forEach(System.out::println);