C# 面向对象5 this关键字和析构函数

this关键字

 1.代表当前类的对象

 2.在类当中显示的调用本类的构造函数(避免代码的冗余)

语法: ":this"

以下一个参数的构造函数调用了参数最全的构造函数!并赋值了那些不需要的属性!

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _04面向对象练习
{
    public class Student
    {
        //字段,属性,方法,构造函数

        

        //构造函数
        public Student(string name,int age,char gender,int chinese,int math,int english)
        {
            //
            this.Name = name;
            this.Age = age;
            this.Gender = gender;
            this.Chinese = chinese;
            this.Math = math;
            this.English = english;
        }

        //******
        //this 关键字的用法
        public Student(string name):this(name,0,'a',0,0,0)
        {
            //this.Name = name;
        }

        public Student()
        {
            Console.WriteLine("Hello!");
        }

        private string _name;
        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }

        private int _age;
        public int Age
        {
            get { return _age; }
            set {
                if (value < 0 || value > 100)
                    value = 0;

                _age = value; }
        }

        private char _gender;
        public char Gender
        {
            get {
                if(_gender !='男'&&_gender!='女')
                   return  _gender='男';

                return _gender; }
            set { _gender = value; }
        }

        private int _chinese;
        public int Chinese
        {
            get { return _chinese; }
            set { _chinese = value; }
        }

        private int _math;
        public int Math
        {
            get { return _math; }
            set { _math = value; }
        }

        private int _english;
        public int English
        {
            get { return _english; }
            set { _english = value; }
        }

        public void SayHello()
        {
            Console.WriteLine("我叫{0},我今年{1}岁了,我是{2}生",this.Name,this.Age,this.Gender);
        }

        public void ShowScore()
        {
            Console.WriteLine("我叫{0},我的总成绩是{1},平均成绩是{2}", this.Name, this.Chinese + this.Math + this.English, (this.Chinese + this.Math + this.English)/3);
        }

    }
}

析构函数

 当程序结束的时候,才会执行析构函数.

作用,不必等GC来回收垃圾,可以调用析构函数马上回收垃圾!!

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _04面向对象练习
{
    public class Student
    {
        //字段,属性,方法,构造函数

        //析构函数
        //当程序结束的时候,析构函数才会执行
        //帮助我们释放资源
        //GC:垃圾回收器可以自动回收垃圾
        //使用析构函数可以马上回收垃圾,不必等GC来回收!
        ~Student()
        {
            Console.WriteLine("析构函数");
        }
        

        //构造函数
        public Student(string name,int age,char gender,int chinese,int math,int english)
        {
            //
            this.Name = name;
            this.Age = age;
            this.Gender = gender;
            this.Chinese = chinese;
            this.Math = math;
            this.English = english;
        }

        //******
        //this 关键字的用法
        public Student(string name):this(name,0,'a',0,0,0)
        {
            //this.Name = name;
        }

        public Student()
        {
            Console.WriteLine("Hello!");
        }

        private string _name;
        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }

        private int _age;
        public int Age
        {
            get { return _age; }
            set {
                if (value < 0 || value > 100)
                    value = 0;

                _age = value; }
        }

        private char _gender;
        public char Gender
        {
            get {
                if(_gender !='男'&&_gender!='女')
                   return  _gender='男';

                return _gender; }
            set { _gender = value; }
        }

        private int _chinese;
        public int Chinese
        {
            get { return _chinese; }
            set { _chinese = value; }
        }

        private int _math;
        public int Math
        {
            get { return _math; }
            set { _math = value; }
        }

        private int _english;
        public int English
        {
            get { return _english; }
            set { _english = value; }
        }

        public void SayHello()
        {
            Console.WriteLine("我叫{0},我今年{1}岁了,我是{2}生",this.Name,this.Age,this.Gender);
        }

        public void ShowScore()
        {
            Console.WriteLine("我叫{0},我的总成绩是{1},平均成绩是{2}", this.Name, this.Chinese + this.Math + this.English, (this.Chinese + this.Math + this.English)/3);
        }

    }
}

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