PHP面向对象之继承的基本思想

图例

概念和说明

代码展示

<?php
    header('content-type:text/html;charset=utf-8');

    //学生考试系统 
    
    class Student{
        public $name;
        public $age;
        //$grade 考分
        private $grade;
        //构造函数
        public function __construct($name, $age){
            $this->name = $name;
            $this->age = $age;
        }
        //评分
        public function setGrade($grade){
            //可以加入对数据的验证..
            $this->grade = $grade;
        }
        //显示分数
        public function showGrade(){
            
            echo '<br> ' . $this->name . ' 成绩是 ' . $this->grade;
        }
    }

    //小学生
    class Pupil extends Student{
        
        //考试函数
        public function testing(){
            
            echo '<br> 小学生在考试...';
        }
    }
    $pupil = new Pupil('小花', 8);
    $pupil->testing();
    $pupil->setGrade(90);
    $pupil->showGrade();

    //大学生考试

    class Graduate extends Student{
                
        //考试函数
        public function testing(){
            
            echo '<br> 大学生在考试...';
        }

    }

    $graduate = new Graduate('大花', 24);
    $graduate->testing();
    $graduate->setGrade(100);
    $graduate->showGrade();