Question

返回垃圾输出。我是PHP的新手。请帮我解决这个问题。我不想永远陷入困境。我是面向对象编程的新手，所以我无法弄清楚出了什么问题以及在哪里！

 <?php
    Abstract class Employee {
        protected $Fname;
        protected $Lname;
        protected $dept;
        static protected $total= '0';
        public abstract function getSalary();
        function __construct($f,$l,$d) {
            $this->Fname = $f;
            $this->Lname = $l;
            $this->dept = $d;
            self::$total++;
        }
        public function getFullname () {
        return $this->Fname." ".$this->Lname;       
        }
        public function getDept() {
        return $this->dept; 
        }
        public static function getTotal(){
            return self::$total;
        }
    }
    class FullTime extends Employee {
        protected $Annualsalary;
        function __construct($s) {
            $this->Annualsalary = $s;
        }
        public function getSalary() {
            return $this->Annualsalary / 12; 
        }
    }
    class Contract extends Employee {
        protected $Monthlypay;
        function __construct ($s)
        {
            $this->Monthlypay = $s;
        }
        public function getSalary() {
            return $this->Monthlypay;

        }
    }


        $emp1 = new FullTime("John",'Doe','IT',150000);
        $emp2 = new FullTime('J','Doe','sales',130000);
        $emp3 = new FullTime('John','D','sales',140000);
        $emp4= new Contract('JOHAN','Doe','sales',14000);
        echo "Total Employees  = ".Employee::getTotal()."<br>";
        echo $emp1->getFullname()." | ".$emp1->getDept()." | ".$emp1->getSalary()."<br>";
        echo $emp2->getFullname()." | ".$emp2->getDept()." | ".$emp2->getSalary()."<br>";
        echo $emp3->getFullname()." | ".$emp3->getDept()." | ".$emp3->getSalary()."<br>";
        echo $emp4->getFullname()." | ".$emp4->getDept()." | ".$emp4->getSalary();
        ?>

输出

员工总数= 0

| | 0

| | 0

| | 0

| | JOHAN

Answer 1

你很亲密。您需要初始化每个类属性，PHP不会自动执行此操作。只需调用父类中的构造函数。此外，您需要将所有参数传递给构造函数。

看看这个：

<?php
    
    Abstract class Employee {
        protected $Fname;
        protected $Lname;
        protected $dept;
        static protected $total = 0;
    
        public abstract function getSalary();
    
        function __construct($f, $l, $d) {
            $this->Fname = $f;
            $this->Lname = $l;
            $this->dept = $d;
            self::$total++;
        }
    
        public function getFullname() {
            return $this->Fname . " " . $this->Lname;
        }
    
        public function getDept() {
            return $this->dept;
        }
    
        public static function getTotal() {
            return self::$total;
        }
    }
    
    class FullTime extends Employee {
        protected $Annualsalary;
    
        function __construct($f, $l, $d, $s) {
            parent::__construct($f, $l, $d);
            $this->Annualsalary = $s;
        }
    
        public function getSalary() {
            return $this->Annualsalary / 12;
        }
    }
    
    class Contract extends Employee {
        protected $Monthlypay;
    
        function __construct($f, $l, $d, $s) {
            parent::__construct($f, $l, $d);
            $this->Monthlypay = $s;
        }
    
        public function getSalary() {
            return $this->Monthlypay;
    
        }
    }
    
    
    $emp1 = new FullTime("John", 'Doe', 'IT', 150000);
    $emp2 = new FullTime('J', 'Doe', 'sales', 130000);
    $emp3 = new FullTime('John', 'D', 'sales', 140000);
    $emp4 = new Contract('JOHAN', 'Doe', 'sales', 14000);
    
    echo "Total Employees  = " . Employee::getTotal() . "<br>";
    echo $emp1->getFullname() . " | " . $emp1->getDept() . " | " . $emp1->getSalary() . "<br>";
    echo $emp2->getFullname() . " | " . $emp2->getDept() . " | " . $emp2->getSalary() . "<br>";
    echo $emp3->getFullname() . " | " . $emp3->getDept() . " | " . $emp3->getSalary() . "<br>";
    echo $emp4->getFullname() . " | " . $emp4->getDept() . " | " . $emp4->getSalary();
    ?>

Answer 2

__构造函数在FullTime类中被覆盖，但不调用父构造函数

function __construct($f,$l,$d, $s) {
 parent::__construct($f,$l,$d);
 $this->Annualsalary = $s;
}

为什么我用这个PHP代码出错了？

2 个答案: