浅谈String中的==和对象中引用对象类型的==

@Test
    public void test02() {
        StringBuffer sb = new StringBuffer();
        sb.append('a');
        sb.append(11);
        System.out.println(sb.toString());
 
        System.out.println("======字符串的引用==========");
        String s1 = new String();
        s1="123";
 
        String s2 = new String();
        s2="123";
        System.out.println(s1);
        System.out.println(s2);
        System.out.println(s1==s2);
        System.out.println(s1=s2);
 
        System.out.println("======引用对象类型==========");
 
        Person p = new Person();
        p.id = 1;
        p.name = "zhangsan";
 
        Person p2 = new Person();
        p2.id = 1;
        p2.name = "zhangsan";
 
        System.out.println(p);
        System.out.println(p2);
        System.out.println(p==p2);
        System.out.println(p.equals(p2));
        System.out.println(p.equals(p));
        System.out.println(p.name.equals(p2.name));
        System.out.println(p=p2);
 
    }
 
    class Person{
            private int id;
            private String name;
 
        @Override
        public String toString() {
            return "Person{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    '}';
        }
    }

　　都是很基础的东西

今天是无聊了，这些基础的东西跑跑也是好的。

造成这些的原因，是与JVM内存机制有关系。

String 常量池

引用对象类型存在于栈Stack中