java 自定义功能界面

Posted 2021-05-07

@FunctionalInterface
public interface MathOperation {
  int operate(int i1, int i2);
}

public static void main(String[] args) {
  MathOperation addition = (i1, i2) -> i1 + i2;
  MathOperation subtraction = (i1, i2) → i1 - i2;
  MathOperation multiplication = (i1, i2) -> i1 * i2;
  MathOperation division = (i1, i2) -> i1 / i2;

  System.out.println("2 + 9 = " + addition.operate(2, 9));
  System.out.println("7 - 5 = " + subtraction.operate(7, 5));
  System.out.println("3 * 7 = " + multiplication.operate(3, 7));
  System.out.println("15 / 5 = " + division.operate(15, 5));
}