函数式编程
@FunctionalInterface
interface Lf{
void dispaly();
}
@FunctionalInterface为显示定义函数时编程接口，不符合函数式编程接口会报错
匿名内部类使用方式
public class FunPrograming {
public static void main(String[] args) {
func func = new func() {
@Override
public void dispaly() {
// TODO Auto-generated method stub
System.out.println("dispaly()运行");
}
};
func.dispaly();
}
}
dispaly()运行
lamada: 拷贝小括号，写死->,落地大括号{}
public class FunPrograming {
public static void main(String[] args) {
func func = ()->{
System.out.println("dispaly()运行");
};
func.dispaly();
}
}dispaly()运行
带返回值的接口
@FunctionalInterface
interface func {//Invalid '@FunctionalInterface' annotation; func is not a functional interface定义两个普通方法就会报错，不符合函数编程
public void dispaly();
public int add(int x,int y);
}
//拷贝小括号，写死->,落地大括号{}
@FunctionalInterface
interface func {
//public void dispaly();
public int add(int x,int y);
}
public class FunPrograming {
public static void main(String[] args) {
func func = (int x,int y)->{
System.out.println("add(int x,int y)运行");
return x+y;
};
System.out.println(func.add(,));
}
}
add(int x,int y)运行
函数式编程接口中如何定义多个方法
@FunctionalInterface
interface func {
default void dispaly() {
System.out.println("default void dispaly()");
}
default int mul(int x ,int y) {
System.out.println("default int mul");
return x* y;
}
static int dec(int x,int y) {
System.out.println("static int dec(int x,int y)");
return x-y;
}
static int div(int x,int y) {
System.out.println("static int div(int x,int y)");
return x/y;
}
public int add(int x,int y);
}