How to iterate List Using Java Stream API?

The List interface is a part of the Java Collection framework and it extends the Collection interface. A list stores a sequence of elements and these elements are searable and accessible using indexes. ArrayList is the most popular implementation of the List interface. A list provides quite precise control over where an element is to be inserted in the List.

List interface provides a stream() method which gives a stream to iterate using forEach method. In forEach method, we can use the lambda expression to iterate over all elements. The following code snippet shows the usage of streams to iterate over the list.

list.stream().forEach(i -> {System.out.print(i + " ");});

In this article, we're discussing use of streams to iterate a list in given examples.

Example 1

Following is the example showing the use of stream API to iterate the list of numbers −

package com.tutorialspoint;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class CollectionsDemo {
   public static void main(String[] args) {
      List<Integer> list = new ArrayList<>(Arrays.asList(1,2,3,4,5));
      list.stream().forEach(i -> {System.out.print(i + " ");});
   }
}

Output

This will produce the following result −

1 2 3 4 5

Example 2

Following is the example showing the use of stream API to iterate the list of string −

package com.tutorialspoint;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class CollectionsDemo {
   public static void main(String[] args) {
      List<String> list = new ArrayList<>(Arrays.asList("A", "B", "C"));
      list.stream().forEach(i -> {System.out.print(i + " ");});
   }
}

Output

This will produce the following result −

A B C