将Lambda表达式转换为方法参考

Question

I was trying to convert a lambda expression into method reference, but I failed to do so. can anybody help me with this? The lambda expression takes 2 int parameters adds it and return the result.

public class Addition {

public static void main(String[] args) {
    int a = 10;
    int b = 20;

    A ref = (int c, int d) -> c + d;
    System.out.println(ref.add(a, b));

}

}

Answer 1

Based on the signature of the method implemented by your lambda expression, you can replace it with:

A ref = Integer::sum;

Since that sum method accepts two int arguments and returns their int sum:

public static int sum(int a, int b) {
    return a + b;
}