# 深入构造器 ## 课堂代码 ~~~java public class Person { private String name; private int age; private String sex; private String work; private String race; public void setName(String name) { this.name = name; } public String getName() { return name; } public void setAge(int age) { this.age = age; } public int getAge() { return age; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public String getWork() { return work; } public void setWork(String work) { this.work = work; } public String getRace() { return race; } public void setRace(String race) { this.race = race; } //在一个类中，是不允许出现方法签名相同的方法的 /** * 一下两个方法实际上执行了方法的重载 * 通俗来讲：就是几个方法，方法名一样，形参不同 * @param foodName * @param count */ public void eatFood(String foodName, int count) { System.out.println("is eating" + foodName); } public String eatFood(String foodName,String count) { return foodName; } public Person() { } /** * 显式的创建出有参的构造器，编译器就不会自动的添加无参构造器 * @param x * @param y */ public Person(String name, int age) { this.name = name;//通过传入的参数，设置成员变量的值 this.age = age; } //使用this(param)调用其他的构造器 public Person(String name, int age, String sex) { //this();//没有参数，this()指的是本类的无参构造器 this(name,age);//所以具体this(param)指的是谁，是由传入的参数类型和个数决定的 this.sex = sex; } /** * 构造器的重载 * @param name * @param age * @param sex * @param work * @param race */ public Person(String name, int age, String sex, String work, String race) { this(name, age, sex); this.work = work; this.race = race; } } ~~~ ~~~java public class Demo { private int a;//只能在本类中被访问 protected int b; public int c; int d; public static void main(String[] args) { String a = "abc"; String b = new String("abc"); System.out.println(a); System.out.println(b); System.out.println(a == b); System.out.println(a.equals(b)); //本类中 Demo demo = new Demo(); demo.a = 10;//private demo.b = 10;//protected demo.c = 10;//public demo.d = 10;//default } } ~~~ ~~~java public class Test { public static void main(String[] args) { //本包中的类中 Demo demo = new Demo(); demo.b = 10;//protected demo.c = 10;//public demo.d = 10;//default //demo.a = 10; private Person person = new Person(); Person person1 = new Person("徐春林", 24, "男"); System.out.println(person1.getName()); System.out.println(person1.getAge()); System.out.println(person1.getSex()); person1.eatFood("x", 1); } } ~~~