2021-04-22 java函数参数

Java提供了函数式编程Function

https://blog.csdn.net/qq_27416233/article/details/84832013

在JDK1.8中，对集合的处理上用的比较多

R apply(T t)

将给定的参数应用到这个函数上,传入的参数类型为T返回类型为R

import java.util.function.Function;

public class FunctionTest {

    public static void main(String[] args) {
        Integer a = new FunctionTest().executeFunction(Calc::add1, 100);
        Integer b = new FunctionTest().executeFunction(Calc::string2Integer, "200");
        System.out.println(a);
        System.out.println(b);
    }

    private <T, R> R executeFunction(Function<T, R> function, T a) {
        R apply = function.apply(a);
        return apply;
    }
}

class Calc {
    public static Integer add1(Integer a) {
        return a + 1;
    }

    public static Integer add2(Integer a) {
        return a + 2;
    }

    public static Integer string2Integer(String str) {
        return Integer.valueOf(str);
    }
}