swift-storage properties, computed properties, class properties

// Class attribute definition

class Student: NSObject {
// Define attributes
// Define storage attributes
    var age: Int = 0
    var name: String?
    
    var mathScore: Double = 0.0
    var chineseScore: Double = 0.0
    
// Define a method that can return the average score (note: swift is not recommended to use this way, a calculated attribute should be defined)
    func getAverageScore ()-> Double {
// If you use a certain property of the current object in swift, or call a method of the current object, you can use it directly without adding self
        return (mathScore chineseScore) * 0.5
    }
    
// Define the calculated attribute: the attribute whose result is calculated in another way is called the calculated attribute
// A lot of calculated attributes
    var averageScore: Double {
        return (mathScore chineseScore) * 0.5
    }
    
// Define class attributes: Class attributes are attributes related to the entire class, and are accessed directly through the class name
// Generally used for more points in simple interest
    static var courceCount: Int = 0
    
}

// Assign values to object properties
let stu = Student ()
stu.age = 10
stu.name = "wj"

stu.mathScore = 78
stu.chineseScore = 70

print (stu.age)

if let name = stu.name {
    print (name)
}

let averageScore = (stu.mathScore stu.chineseScore) * 0.5

let ave = stu.averageScore

// Class attributes
// Assign values to class attributes
Student.courceCount = 2 

swift-storage properties, computed properties, class properties