java - LightYear与num - 2.1 - 2.2 - 一光年的距离 - 数据类型

java - HelloWord与java.util.Scanner - 1.1 - 1.2 - 你好，世界！ - 计算圆的面积

java - 一个员工示例 {card-default label="Employee.java" width=""}import java.io.*; public class Employee { String name; int age; String designation; double salary; //Employee类的构造器 public Employee(String name){ this.name = name; } //设置age public void empAge(int empAge){ age = empAge; } //设置designation的值 public void empDesignation(String empDesig){ designation = empDesig; } //设置salary的值 public void empSalary(double empSalary){ salary = empSalary; } //打印信息 public void printEmployee(){ System.out.println("姓名" + name); System.out.println("年龄" + age); System.out.println("职位" + designation); System.out.println("薪水" + salary); } } {/card-default}{card-default label="EmployeeText.java" width=""}import java.io.*; public class EmployeeText { public static void main(String[] args){ /* 使用构造器创建两个对象 */ Employee empOne = new Employee("RUNOOB1"); Employee empTwo = new Employee("RUNOOB2"); // 调用这两个对象的成员方法 empOne.empAge(26); empOne.empDesignation("高级程序员"); empOne.empSalary(1000); empOne.printEmployee(); empTwo.empAge(21); empTwo.empDesignation("菜鸟程序员"); empTwo.empSalary(500); empTwo.printEmployee(); } } {/card-default}

java - 一个宠物示例 {card-default label="Puppy.java" width=""}public class Puppy { //类名必须与文件名同名 int puppyAge; public Puppy(String name){ //一个参数 name System.out.println("小狗的名字是" + name); } public void setAge(int age){ puppyAge = age; } public int getAge(){ System.out.println("小狗的年龄为：" + puppyAge); return puppyAge; } public static void main(String[] args){ //创建一个Puppy对象 Puppy myPuppy = new Puppy("tommy"); //通过方法设定age myPuppy.setAge(2); //调用另一个方法获取age myPuppy.getAge(); //直接打印出变量值 System.out.println("变量值为：" + myPuppy.puppyAge); } } {/card-default}

java - 数据类型 数据类型取值范围所占位数byte-128 ~ 1278short-2^15 ~ 2^15 -116int-2^31 ~ 2^31 -132long-2^63 ~ 2^63 -164float约 1.4X10^-45 ~ 3.4X10^3832double约 4.9X10^-432 ~ 1.79X10^30864boolean只有true和false两个值1char0 ~ 6553516