第5章 面向对象(基础篇)
1、
class Address { private String country; private String province; private String city; private String street; private String postcode; Address() { } Address(String country, String province, String city, String street, String postcode) { this.country = country; this.province = province; this.city = city; this.street = street; this.postcode = postcode; } public void show() { System.out.println("地址为:"+country+province+city+street+" 邮编: "+postcode); } } public class AddressTest { public static void main(String[] args) { new Address("中国", "湖北省", "天门市", "陆羽大道", "427806").show(); } }
2、
class Employee { private String id; private String name; private double base_salary; private double increase_salary; Employee(String id, String name, double base_salary, double increase_salary) { this.id = id; this.name = name; this.base_salary = base_salary; this.increase_salary = increase_salary; } public double getIncrease_salary() { return increase_salary; } public double getTotalSalary() { return increase_salary + base_salary; } } public class EmployeeDemo { public static void main(String[] args) { Employee li = new Employee("211016040", "李阿昀", 5000, 2500.50); System.out.println("薪水增长额:"+li.getIncrease_salary()); System.out.println("增长后的工资总额为:"+li.getTotalSalary()); } }
3、
public class practice3 { public static void main(String[] args) { String str = "want you to know one thing"; System.out.println("字母n出现的次数:"+getCharacterCounts(str, 'n')); System.out.println("字母o出现的次数:"+getCharacterCounts(str, 'o')); } public static int getCharacterCounts(String str, char ch) { int count = 0; for(int index = 0; (index = str.indexOf(ch, index)) != -1; index++) { count++; } return count; } }
4、
class Dog { private String name; private String color; private int age; public Dog(String name, String color, int age) { this.name = name; this.color = color; this.age = age; } public void show() { System.out.println("狗狗的名字是"+name+",颜色是"+color+",年龄是"+age+"岁。"); } } public class DogTest { public static void main(String[] args) { new Dog("旺财", "黄色", 5).show(); } }
5、
class User { private String name; private String psw; private static int count = 0; User() { count++; System.out.println("创建第"+count+"个对象。"); } User(String name) { this.name = name; count++; System.out.println("创建第"+count+"个对象。"); } User(String name, String psw) { this.name = name; this.psw = psw; count++; System.out.println("创建第"+count+"个对象。"); } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPsw() { return psw; } public void setPsw(String psw) { this.psw = psw; } public void show() { System.out.println("用户名:"+name+",口令:"+psw); } } public class UserTest { public static void main(String[] args) { new User().show(); new User("叶子").show(); new User("李阿昀", "liayun").show(); } }
6、
public class StringTest { public static void main(String[] args) { getTime("Java 技术学习班 20070326"); replace("MLDN JAVA", "JAVA", "J2EE"); getChar("Java 技术学习班 20070326", 8); clear_0("Java 技术学习班 20070326", '0'); clear_space("Java 技术学习班 20070326"); getBirthday("429006199210061852"); } //(1) public static void getTime(String str) { int index = str.indexOf('2'); int year = Integer.parseInt(str.substring(index, index + 4)); int month = Integer.parseInt(str.substring(index + 4, index + 6)); int day = Integer.parseInt(str.substring(index + 6)); System.out.println("开班日期:"+year+"年"+month+"月"+day+"日"); } //(2) public static void replace(String str, String oldStr, String newStr) { System.out.println("替换之后的字符串为:"+str.replaceAll(oldStr, newStr)); } //(3) public static void getChar(String str, int index) { System.out.println("\""+str+"\""+"中第"+index+"个字符为:"+str.charAt(index)); } //(4) public static void clear_0(String str, char ch) { str = str.replaceAll("0", ""); System.out.println("\""+str+"\""+"清除所有的0后为:"+str); } //(5) public static void clear_space(String str) { String[] s = str.split(" "); System.out.print("\""+str+"\""+"清除所有的空格后为:"); for(int x = 0; x < s.length; x++) { System.out.print(s[x]); } System.out.println(); } //(6) public static void getBirthday(String birthday) { int year = Integer.parseInt(birthday.substring(6, 10)); int month = Integer.parseInt(birthday.substring(10, 12)); int day = Integer.parseInt(birthday.substring(12, 14)); System.out.println("身份证号为("+birthday+")人的生日为:"+year+"年"+month+"月"+day+"日"); } }
7、
package chapter5; class Staff { private String id; private String name; private double salary; private String department; public Staff(String id) { this.id = id; name = "无名氏"; salary = 0; department = "未定"; } public Staff(String id, String name) { this.id = id; this.name = name; salary = 1000; department = "后勤"; } public Staff(String id, String name, double salary, String department) { this.id = id; this.name = name; this.salary = salary; this.department = department; } public Staff() { } public void show() { System.out.println("员工信息为--->工号:"+id+",姓名:"+name+",薪水:"+salary +",部门:"+department); } } public class StaffTest { public static void main(String[] args) { new Staff().show(); new Staff("001").show(); new Staff("002", "李阿昀").show(); new Staff("003", "李子", 25000.5, "研发部").show(); } }
8、
package chapter5; public class Account { private String accontName; private double balance; public Account(String accontName, double balance) { this.accontName = accontName; this.balance = balance; } public double getBalance() { return balance; } }
9、
class Book { private String title; private String id; private double price; private static int count = 0;//静态数据成员册数 Book(String title, double price) { this.title = title; this.id = "00"+(++count); this.price = price; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getId() { return id; } public void setId(String id) { this.id = id; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public static int getCount() { return count; } } public class BookTest { public static void main(String[] args) { Book[] books = {new Book("小王子", 34.5), new Book("西游记", 56.5), new Book("Thinking In Java", 34.5)}; for(int x = 0; x < books.length; x++) { System.out.println("编号:"+books[x].getId()+",书名:"+books[x].getTitle()+ "价格:"+books[x].getPrice()); } System.out.println("图书的总册数为:"+Book.getCount()+"册"); } }