92、（案例）使用Lambda实现一个加法器案例

public interface Demo04Calculator {
    abstract int sum(int a, int b);
}

public class Demo04 {
    public static void main(String[] args) {
        //标准给是
        invokeSum(10, 20, new Demo04Calculator() {
            @Override
            public int sum(int a, int b) {
                return a + b;
            }
        });

        //Lambda
        invokeSum(100, 200, (int a, int b)-> {
                return a + b;
        });

        //Lambda ---简化版
        invokeSum(50, 200, (int a, int b)-> a + b);

    }
    public static void invokeSum(int a, int b, Demo04Calculator cal){
        int res = cal.sum(a, b);
        System.out.println("结果是："+ res);
    }
}