Java Program to pass lambda expression as a method argument

Example 1: Define lambda expressions as method parameters

Output

ArrayList: [java, swift, python]
Updated ArrayList: [JAVA, SWIFT, PYTHON]

In the above example, we have created an arraylist named languages. Notice the line,

languages.replaceAll(e -> e.toUpperCase());

Here, e -> e.toUpperCase() is a lambda expression. It takes all elements of the arraylist and converts them into uppercase.

Example 2: Pass multiline lambda body as function arguments

Output

ArrayList: [java, python]
Reversed ArrayList: avaj, nohtyp,

In the above example, we have created an arraylist languages. Notice the line,

    languages.forEach((e) -> {

      // body of lambda expression
      String result = "";
      for (int i = e.length()-1; i >= 0 ; i--)
      result += e.charAt(i);
      System.out.print(result + ", ");
    });

Here, we are passing lambda expression as an argument to the ArrayList forEach() method. The lambda expression will reverse each element of the arraylist.