//类
class Student: NSObject{
    
    //存储属性:
    var age :Int=0
    var name:String?
    var mathscore:Double=0.0
    var chinesescore:Double=0.0
    
    //计算属性; 平均成绩
    var averageScroe:Double{
        
     return(mathscore+chinesescore)/2;

    }
    
    //定义类属性：类属性是和整个类相关的属性，而且是通过类名进行访问的
    static var courseCount:Int=0
    
    
    
}


//给类属性进行赋值
Student.courseCount=2;

//创建对象
let p=Student()
//对象属性赋值
p.age=10
p.name="哈哈"
p.mathscore=99.1
p.chinesescore=34.2
print(p.averageScroe)