浅谈Java中Lambda表达式的相关操作

// 实现接口，同时必须重写接口中抽象方法
class Test implements IntrfacefN {
    @Override
    public void getUser(int a, int b) {
    }
}
// @FunctionalInterface 注解意思：函数式接口，用来做规范，有这个注解，说明此接口有且只有一个抽象方法！！！ 
@FunctionalInterface
interface IntrfacefN{
    public void getUser(int a, int b);
}

public class Lamda {
    public static void main(String[] args) {
        // 匿名表达式实现接口
        IntrfacefN intrfacefN1 = new IntrfacefN(){
            @Override
            public void getUser(int a, int b) {
                
            }
        };
    }
}

public class Lamda {
    public static void main(String[] args) {
        // 实现接口，后边匿名函数就是重写的方法！
        IntrfacefN intrfacefN = (int a, int b) -> System.out.println(a-b);
        intrfacefN.getUser(1, 2);
    }
}

@FunctionalInterface
interface IntrfacefN{
    public void getUser(int... a);
}
public class Lamda {
    public static void main(String[] args) {
        IntrfacefN intrfacefN = (int ...a) -> {
            for (int i = 0; i < a.length; i ++) {
                System.out.println(a[i]);
            }
        };
        intrfacefN.getUser(1, 2);
    }
}

IntrfacefN intrfacefN = (a, b) -> System.out.println(a-b);

IntrfacefN intrfacefN = a -> System.out.println(a);

IntrfacefN intrfacefN = (a, b) -> System.out.println(a-b);

IntrfacefN intrfacefN = (a, b) -> {
    return a-b
};
// 省略之后写法：
IntrfacefN intrfacefN = (a, b) -> a-b;

public class Lamda {
    public static void main(String[] args) {
        IntrfacefN intrfacefN = (a, b) -> add(a, b);
        intrfacefN.getUser(1, 2);
    }
    public static void add(int a, int b) {
        System.out.println(a+b);
    }
}
 
@FunctionalInterface
interface IntrfacefN{
    public void getUser(int a, int b);
}

public class Lamda {
    public static void main(String[] args) {
        IntrfacefN intrfacefN = Lamda::add;
        intrfacefN.getUser(1, 2);
    }
    public static void add(int a, int b) {
        System.out.println(a+b);
    }
}
 
@FunctionalInterface
interface IntrfacefN{
    public void getUser(int a, int b);
}