JAVA的类
类与调用
1 public class initCal { 2 private int num1; 3 private int num2; 4 private char option; 5 6 public void harvest(int n1, int n2, char o) { 7 num1 = n1; 8 num2 = n2; 9 if (o == '+' || o == '-' || o == '*' || o == '/') { 10 option = o; 11 } 12 } 13 public void cal() { 14 switch (option) { 15 case '+': 16 System.out.println(num1 + num2); 17 break; 18 case '-': 19 System.out.println(num1 - num2); 20 break; 21 case '*': 22 System.out.println(num1 * num2); 23 break; 24 case '/': 25 System.out.println(num1 / num2); 26 break; 27 default: 28 break; 29 } 30 } 31 }
1 public class cpu { 2 3 public static void main(String[] args) { 4 initCal c = new initCal(); 5 c.harvest(1, 2, '+'); 6 c.cal(); 7 } 8 }
构造函数
1 class baby { 2 int num1; 3 String str1; 4 5 //构造代码块在创建对象的时候就会执行 创建一次,执行一次 6 { 7 System.out.println("构造代码块执行了"); 8 } 9 10 public baby(int n1, String s1) { 11 this.num1 = n1; 12 this.str1 = s1; 13 } 14 15 public static void main(String[] args) { 16 baby ba = new baby(1, "hello"); 17 baby ba2 = new baby(1, "hello"); 18 } 19 }
抽象类 继承
Animal类
1 abstract class Animal { 2 String name; 3 String color; 4 5 public Animal(String name,String color) { 6 this.name=name; 7 this.color; 8 } 9 10 public void eat() { 11 System.out.print("吃东西"); 12 } 13 14 public abstract void run(); 15 }
Dog类
1 public class Dog extends Animal { 2 3 public Dog(String name, String color) { 4 super(name, color); 5 } 6 7 public void run() { 8 System.out.print(color + name + "四条腿跑"); 9 } 10 11 public static void main(String[] args) { 12 Dog dg = new Dog("海狗", "黄色"); 13 dg.run(); 14 } 15 16 }
Fish类
1 public class fish extends Animal { 2 3 public fish(String name, String color) { 4 super(name, color); 5 // TODO Auto-generated constructor stub 6 } 7 8 public void run() { 9 System.out.print(color + name + "游的快"); 10 } 11 12 public static void main(String[] args) { 13 fish fh = new fish("小鱼", "红色"); 14 fh.run(); 15 } 16 17 }