编辑代码

protocol classa {
    
    var marks: Int { get set }
    var result: Bool { get }
    
    func info() -> String
    
}

protocol classb: classa {
    
    var stname: String { get set }
    
}

class classc: classb {
    var marks :Int = 0
    var result: Bool = false
    var stname :String  = "张三"
    /*
    init(marks:Int,result:Bool,stname:String){
        self.marks = marks
        self.result = result
        self.stname = stname
    }
    */

    func info() -> String{
        if marks > 60{
            result = true
        }
        else{
            result = false
        }

        if result == true{
            return "\(stname)得分：\(marks),成功通过考试"
        }
        else{
            return "\(stname)得分：\(marks),未通过考试"
        }
    }
    
}

let stu = classc()
stu.marks = 18
stu.stname = "刘辉"

print(stu.info())