OnJava8-Examples/functional/LambdaExpressions.java

// functional/LambdaExpressions.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.

interface Description {
  String brief();
}

interface Body {
  String detailed(String head);
}

interface Multi {
  String twoArg(String head, Double d);
}

public class LambdaExpressions {

  static Body bod = h -> h + " No Parens!"; // (1)

  static Body bod2 = (h) -> h + " More details"; // (2)

  static Description desc = () -> "Short info"; // (3)

  static Multi mult = (h, n) -> h + n; // (4)

  static Description moreLines = () -> { // (5)
    System.out.println("moreLines()");
    return "from moreLines()";
  };

  public static void main(String[] args) {
    System.out.println(bod.detailed("Oh!"));
    System.out.println(bod2.detailed("Hi!"));
    System.out.println(desc.brief());
    System.out.println(mult.twoArg("Pi! ", 3.14159));
    System.out.println(moreLines.brief());
  }
}
/* Output:
Oh! No Parens!
Hi! More details
Short info
Pi! 3.14159
moreLines()
from moreLines()
*/