JAVA 学习笔记.docx

文档介绍：(一). 类
(一). 1
public class EmpInfo
{
private int empId, age; // 定义整形(int)变量
private String name, sex, job; // 定义字符串(String)变量
private float sal; // 定义浮点数(float)变量

public EmpInfo(){} // 定义无参函数
public EmpInfo(int _empId, String _name, String _sex, int _age, String _job, float _sal)
{
empId = _empId; // 将形参中的值传入变量
age = _age;
name = _name;
sex = _sex;
job = _job;
sal = _sal;
}
public void displayEmp() // 定义一个没有返回值的函数
{
(" 编号姓名性别年龄工作工资");
(" "+empId +" "+name+" "+sex+" "+age+" "+job+" "+sal+" ");
}
}
(一). 2 测试类
public class EmpInfoApp
{
public static void main(String[] args) // main函数,可调用
{
EmpInfo ef = new EmpInfo(2015, "王总", "男", 21,"经理", ); // 赋值
();
}
}

(二). 类
(二).1
public class Sal
{
private int salId, sals;
private String salName, job, loc;
public Sal(){}
public Sal(int _salId, String _salName, int _sals, String _job, String _loc)
{
salId = _salId;
salName = _salName;
sals = _sals;
job = _job;
loc = _loc;
}
public void Salf()
{
("编号姓名工资工作地址");
(" "+salId+" "+salName+" "+sals+" "+job+" "+loc+" ");
}
}
(二).2 测试类
public class Salno
{
public static void main(String[] args)
{
Sal eg = new Sal(99, "张大伟", 8888, "工程师", "西门街");
();
}
}
(三).解决继承类不能访问私有变量。
(三).1当私有变量不能被访问,使用get函数方法。
public class EmpInfo
{
private int empId, age;
private String name, sex, job;
private float sal;

public EmpInfo(){}
public EmpInfo(int _empId, String _name, String _sex, int _age, String _job, float _sal)
{
empId = _empId;
age = _age;
name = _name;
sex = _sex;
job = _job;
sal = _sal;
}
public void displayEmp()
{
(" 编号姓名性别年龄工作工资");
(" "+empId +" "+name+" "+sex+" "+age+" "+job+" "+sal+" ");
}
public int getEmpId()
{
return empId;
}
public String getName()
{
return name;
使用get函数返回值的方法,使私有变量可以被访问!
}
public String getSex