Java学习——变量类型

package import_test;

public class Dog {
    public void pupAge(){
        int age = 1;
        int color;
        System.out.println("小狗的年龄是:" + age);
    }
    public static void main(String args[]){
        Dog test = new Dog();
        test.pupAge();
    }
}

package import_test;

public class Dog {
    public void pupAge(){
        int age;
        age = age + 1;
        System.out.println("小狗的年龄是:" + age);
    }
    public static void main(String args[]){
        Dog test = new Dog();
        test.pupAge();
    }
}

package import_test;

public class Employee{
    // 这个成员变量对子类可见
    public String name;
    // 私有变量，仅在该类可见
    private double salary;
    //在构造器中对name赋值
    public Employee (String empName){
        name = empName;
    }
    //设定salary的值
    public void setSalary(double empSal){
        salary = empSal;
    }

    public void printEmp(){
        System.out.println("name  : " + name );
        System.out.println("salary :" + salary);
    }

    public static void main(String args[]){
        Employee empOne = new Employee("Jim");
        empOne.setSalary(2000);
        empOne.printEmp();
    }
}

name  : Jim
salary :2000.0

import java.io.*;
public class Employee {
    //salary是静态的私有变量
    private static double salary;
    // DEPARTMENT是一个常量
    public static final String DEPARTMENT = "开发人员";
    public static void main(String args[]){
    salary = 10000;
        System.out.println(DEPARTMENT+"平均工资:"+salary);
    }
}

开发人员平均工资:10000.0
开发人员平均工资：10000.0