我想在 PHP OOP 中的另一个方法中使用一个方法

Question

我想像这样实例化一个对象：

$foo=new myClass();
$foo->method1()->method2();

如何为此设置 class？

Answer 1

你需要在这个方法中return $this 例如：

class A
{
     function first()
     {
         //do some stuff
          return $this;
     }
     function second()
     {
         //do some stuff
          return $this;
     }
}

$obj = new A();
$obj->first()->second();

有一个模式“Fluent intarface", some simple example. And check this。

Answer 2

我认为您的代码应该如下所示：

（代码不完整，应该只是给出它如何工作的想法）

<?php

    class Database {

        private $hostname = "localhost";
        private $dbName = "dbName";
        private $username = "root";
        private $password = "";

        private $connection;

        private $queryString = "";

        public function __construct($hostname, $dbName, $username, $password) {

            $this->hostname = $hostname;
            $this->dbName = $dbName;
            $this->username = $username;
            $this->password = $password;

            try {
                $this->connection = new PDO("mysql:host=" . $this->hostname . ";dbname=" . $this->dbName . "", $this->username, $this->password);
                $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

            } catch(PDOException $e) {
                echo $e->getMessage();
            }

        }

        public function Close() {
            $this->connection = null;
        }

        public function Select($select) {

            $this->queryString .= "SELECT $select";

            return $this;

        }

        public function From($from) {

            $this->queryString .= " FROM $from";

            return $this;

        }

        public function Where($column, $value) {

            $this->queryString .= " WHERE $column = '$value'";

            return $this;

        }

        public function execute() {

            $stmt = $this->connection->prepare($this->queryString);
            $stmt->execute();

        }




    }

    $db = new Database("localhost", "dbName", "root", "");
    $db->Select("id")->From("xy")->Where("name", "peter")->execute();

?>

我想在 PHP OOP 中的另一个方法中使用一个方法

I want to use a method inside another method in PHP OOP

php

oop