Pass Lambda Expression as Method Argument in Java

Exercise:

Write a Java Program to pass lambda expression as a method argument.

Click Here to View the Solution!
import java.util.ArrayList;

class lambda {
    public static void main(String[] args) {
        ArrayList<String> city = new ArrayList<>();
       
        // add elements to the ArrayList city
        city.add("London");
        city.add("New York");
        city.add("Washington");
        System.out.println("ArrayList: " + city);
      
        // pass lambda expression as parameter
        city.replaceAll(e -> e.toUpperCase());
        System.out.println("Updated ArrayList: " + city);
    }
}
Click Here to View the Output!
 ArrayList: [London, New York, Washington]
 Updated ArrayList: [LONDON, NEW YORK, WASHINGTON]
Click Here to View the Explanation!
  • In this program, firstly an arraylist called city is created.
  • Next, elements in lowercase letters are added to this arraylist by the arraylist method called add().
  • After adding elements in the list, arraylist is displayed on the screen.
  • Lastly, all the elements in the list are replaced by their uppercase versions using the lambda expression. Notice the expression below: languages.replaceAll(e -> e.toUpperCase()); toUpperCase() method takes a string and converts all of its letters into uppercase.