技術標籤：java

引用資料型別最大的特點是可以進行記憶體的指向處理 不同方法名描述同一個方法

自有定義：

@FunctionalInterface
public interface Function<T,R>{
    public R apply(T t) ;
}
@FunctionalInterface
public interface Consumer<T>{
    public void accept(T t) ;
}
@FunctionalInterface
public interface Supplier<T>{
    public
 
 T get() ;
}
//斷言函式式介面 進行判斷處理 equalsIgnareCase()
@FunctionalInterface
public interface Predicate<T>{
    public boolean test(T t) ;
}

程式碼：

package com.msc.example;

import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.
 
Supplier;

interface  IFunction<K,R>{
    public K change(R r);
}
interface  IFunctionb<R>{
    public R upper();
}
interface  IFunctionc<P>{
    public int compare(P p1,P p2);
}
interface  IFunctiond<P>{
    public P create(String n,int a);
}
class Example{
    private String name ;
 

    private int age ;
    public Example(String namr,int age){
        this.age = age ;
        this.name = name ;
    }

    @Override
    public String toString() {
        return "Example{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}
public class FunctionDemo {
    public static void main(String[] args) {
        IFunction<String,Integer> fun = String :: valueOf;
        IFunctionb<String> funb = "test" :: toUpperCase;
        IFunctionc<String> func = String :: compareTo;
        IFunctiond<Example> fund = Example::new ;
        String str = fun.change(100) ;
        System.out.println(str);
        System.out.println(funb.upper());
        System.out.println(func.compare("A","a"));
        System.out.println(fund.create("里斯",20));
        System.out.println("-------------------------------");
        Function<String,Boolean> funl = "**hello" :: startsWith;
        System.out.println(funl.apply("**"));
        Consumer<String> con = System.out :: println;
        con.accept("Consumer");
        Supplier<String> sup = "com.mSc.cn" :: toLowerCase;
        System.out.println(sup.get());
        Predicate<String> pre = "com" :: equalsIgnoreCase;
        System.out.println(pre.test("Com"));
    }
}