復(fù)制代碼 代碼如下:
<?php
class db {
    private $mysqli; //數(shù)據(jù)庫(kù)連接
    private $options; //SQL選項(xiàng)
    private $tableName; //表名
    public function __construct($tabName) {
        $this->tableName = $tabName;
        $this->db ();
    }
    private function db() {
        $this->mysqli = new mysqli ( 'localhost', 'root', '', 'hdcms' );
        $this->mysqli->query("SET NAMES GBK");
    }
    public function fields($fildsArr) {
        if (empty ( $fildsArr )) {
            $this->options ['fields'] = '';
        }
        if (is_array ( $fildsArr )) {
            $this->options ['fields'] = implode ( ',', $fildsArr );
        } else {
            $this->options ['fields'] = $fildsArr;
        }
        return $this;
    }
    public function order($str) {
        $this->options ['order'] = "ORDER BY " . $str;
        return $this;
    }
    public function select() {
        $sql = "SELECT {$this->options['fields']} FROM {$this->tableName}  {$this->options['order']}";
        return $this->query ( $sql );
    }
    private function query($sql) {
        $result = $this->mysqli
            ->query ( $sql );
        $rows = array ();
        while ( $row = $result->fetch_assoc () ) {
            $rows [] = $row;
        }
        return $rows;
    }
    private function close() {
        $this->mysqli
            ->close ();
    }
    function __destruct() {
        $this->close ();
    }
}
$chanel = new db ( "hdw_channel" );
$chanelInfo = $chanel->fields ( 'id,cname,cpath' )
    ->select ();
echo "<pre>";
print_r ( $chanelInfo );

class a {
    protected  function aa(){
        echo 222;
    }
}
class b extends a{
    function bb(){
        $this->aa();
    }
}
$c = new b();
$c->bb();

public   公有的：本類(lèi)，子類(lèi)，外部對(duì)象都可以調(diào)用
protected 受保護(hù)的：本類(lèi) 子類(lèi)，可以執(zhí)行，外部對(duì)象不可以調(diào)用
private 私有的：只能本類(lèi)執(zhí)行，子類(lèi)與外部對(duì)象都不可調(diào)用

php技術(shù)：php學(xué)習(xí)筆記之面向?qū)ο缶幊?/a>，轉(zhuǎn)載需保留來(lái)源！