class Employee{ private static int nextID = 1; private int id;}在Employee对象中，每个对象都有（）字段，所有对象共享（）字段
举一反三
- 有如下类的定义，创建Employee对象正确的是（） public class Employee{ private int age; private String name; public void Employee(){ } public Employee(int age){ this.age = age; } public Employee(String name){ this.name = name; } } A: Employee e = new Employee( ) B: Employee e = new Employee(10); C: Employee e = new Employee(tom); D: Employee e = new Employee(10,"tom");
- 有如下类的定义，创建Employee对象错误的是（） public class Employee{ private int age; private String name; public Employee(int age){ this.age = age; } public Employee(String name){ this.name = name; } public Employee(int age,String name){ this(age); this.name = name; } } A: Employee emp = new Employee(10); B: Employee emp = new Employee("Tom"); C: Employee emp = new Employee(); D: Employee emp = new Employee(10,"Tom");
- 关于Employee类的对象说法错误的是（） public class Employee{ private int age; private String name; public Employee(){ } public Employee(int age,String name){ this.age = age; this.name = name; } } public class TestEmployee{ public static void main(String[] args){ Employee e1 = new Employee(); Employee e2 = new Employee(10,"tom"); Employee e3 = e2; Employee e4 = new Employee(10,"tom"); } } A: e1对象的name和age属性的值是默认值null和0 B: e2和e3指向相同的内存空间，即指向同一个对象 C: e3和e4对象的age属性值都是10，name属性值都是"tom"，所以是同一个对象 D: 表达式e2==e3的值为true，e3==e4的值为false
- 现有表Employee，字段：id（int）、firstname（varchar）、lastname（varchar）；以下sql语句错误的是（）
- 在Java中，创建对象必须使用的关键字是【 】 A: class B: int C: new D: private