X32专项练习部分09

• 双向链表的搜索速度方差
• 适合存放数据元素的结构
• 有无符号位运算
• 类变量和局部变量
• (important)依赖注入和控制反转
• Integer自动装箱
• 构造方法赋值
• 代码块执行顺序
• 总目录

		public static void main(String[] args) {
            
            System.out.println(20 >>> 2); // 5
            System.out.println(-20 >> 2); // -5
            System.out.println(-20 >>> 2); // 1073741819
        }

class Test {
    public static int a = 1;
    public static void main(String[] args) {
        int a = 10;
        a++; // 类变量+1
        Test.a++; // 局部变量+1
        Test t=new Test();
        System.out.println("a=" + a + " t.a=" + t.a);
        // a = 11 t.a = 2
        
    }
}

// 解耦前
class Main {
    public static void main(String[] args) {
        
        Chinese chinese = new Chinese();
        chinese.sayHelloWorld("张三");

        American american = new American();
        american.sayHelloWorld("Jack");
    }
}

interface Human {
    public void sayHelloWorld(String name);
}


class Chinese implements Human {
    public void sayHelloWorld(String name) {
        String helloWorld = "你好，" + name;
        System.out.println(helloWorld);
    }
}

class American implements Human {
    public void sayHelloWorld(String name) {
        String helloWorld = "Hello，" + name;
        System.out.println(helloWorld);
    }
}

// 解耦后
class Main {
    public static void main(String[] args) {
        
        HumanFactory humanFactory = new HumanFactory();
        Human human1 = humanFactory.getHuman("chinese");
        human1.sayHelloWorld("张三");

        Human human2 = humanFactory.getHuman("american");
        human2.sayHelloWorld("Jack");
    }
}

interface Human {
    public void sayHelloWorld(String name);
}

class HumanFactory {
    public Human getHuman(String type) {
        if ("chinese".equals(type)) {
            return new Chinese();
        } else {
            return new American();
        }
    }
}

class Chinese implements Human {
    public void sayHelloWorld(String name) {
        String helloWorld = "你好，" + name;
        System.out.println(helloWorld);
    }
}

class American implements Human {
    public void sayHelloWorld(String name) {
        String helloWorld = "Hello，" + name;
        System.out.println(helloWorld);
    }
}

		
        Integer a1 = 1;
        Integer b1 = 1;
        Integer c1 = 500;
        Integer d1 = 500;
        System.out.print(a1 == b1); // true
        System.out.print(c1 == d1); // false
        

class TestDemo{
    private int count;
    public static void main(String[] args) {
        TestDemo test=new TestDemo(88);
        System.out.println(test.count); // 88
    }
    TestDemo(int a) {
        
        count=a;
    }
}

class HelloA {
    public HelloA() {
        System.out.println("A的构造函数");
    }
    {
        System.out.println("A的构造代码块");
    }
    static {
        System.out.println("A的静态代码块");
    }
    public static void main(String[] args) {
        HelloA a = new HelloA();
    }
}