成员方法

public class juxing {
    
    juxing(){
        chang=1;
        kuan=1;
    }
    
    double chang;
    
    double kuan;
    
    double mianji(){
        
        return (chang*kuan);
    }
    
    public static void mian(String []ages){
        
        juxing a=new juxing();
        
        a.chang=3.2;
        
        a.kuan=2.4;
        
        System.out.println("呵呵哒"+a.mianji());
        
    }
}

public static void main(String[] args) {
        // TODO 自动生成的方法存根

        juxing a=new juxing();
        System.out.println(a.mianji());
        
        a.chang=3.2;
        
        a.kuan=2;
        
        System.out.println(a.mianji());
    }

public class 运算 {

    double 数字一;
    
    double 数字二;
    
    double a2;
    
    void 运算方式 (String a){
        switch(a){
        case "加":
            a2=数字一+数字二;
            System.out.println(a2);
        break;
        case "+":
            a2=数字一+数字二;
            System.out.println(a2);
        break;
        case "-":
            a2=数字一-数字二;
            System.out.println(a2);
        break;
        case "减":
            a2=数字一-数字二;
            System.out.println(a2);
        break;
        case "*":
            a2=数字一-数字二;
            System.out.println(a2);
        break;
        case "乘":
            a2=数字一*数字二;
            System.out.println(a2);
        break;
        case "/":
            a2=数字一-数字二;
            System.out.println(a2);
        break;
        case "除":
            a2=数字一/数字二;
            System.out.println(a2);
        break;
        case "%":
            a2=数字一%数字二;
            System.out.println(a2);
        break;
        case "摩":
            a2=数字一-数字二;
            System.out.println(a2);
        break;
        default :
            System.out.println("别逗好么，我问你你怎么算");
        }
    }

public static void main(String[] args) {
        // TODO 自动生成的方法存根
        运算 a=new 运算();
        a.数字一=10.2;
        a.数字二=3.3;
        a.运算方式("/");