解析错误：语法错误，意外'['in

Question

我不断收到错误消息Parse error: syntax error, unexpected '[' in ... in line 3，并带有以下代码：

class IPTC
{
    var $meta = [];
    var $file = null;

    function __construct($filename)
    {
        $info = null;

        $size = getimagesize($filename, $info);

        if(isset($info["APP13"])) $this->meta = iptcparse($info["APP13"]);

        $this->file = $filename;
    }

    function getValue($tag)
    {
        return isset($this->meta["2#$tag"]) ? $this->meta["2#$tag"][0] : "";
    }

    function setValue($tag, $data)
    {
        $this->meta["2#$tag"] = [$data];

        $this->write();
    }

    private function write()
    {
        $mode = 0;

        $content = iptcembed($this->binary(), $this->file, $mode);   

        $filename = $this->file;

        if(file_exists($this->file)) unlink($this->file);

        $fp = fopen($this->file, "w");
        fwrite($fp, $content);
        fclose($fp);
    }         

    private function binary()
    {
        $data = "";

        foreach(array_keys($this->meta) as $key)
        {
            $tag = str_replace("2#", "", $key);
            $data .= $this->iptc_maketag(2, $tag, $this->meta[$key][0]);
        }       

        return $data;
    }

    function iptc_maketag($rec, $data, $value)
    {
        $length = strlen($value);
        $retval = chr(0x1C) . chr($rec) . chr($data);

        if($length < 0x8000)
        {
            $retval .= chr($length >> 8) .  chr($length & 0xFF);
        }
        else
        {
            $retval .= chr(0x80) . 
                       chr(0x04) . 
                       chr(($length >> 24) & 0xFF) . 
                       chr(($length >> 16) & 0xFF) . 
                       chr(($length >> 8) & 0xFF) . 
                       chr($length & 0xFF);
        }

        return $retval . $value;            
    }   

    function dump()
    {
        echo "<pre>";
        print_r($this->meta);
        echo "</pre>";
    }

    #requires GD library installed
    function removeAllTags()
    {
        $this->meta = [];
        $img = imagecreatefromstring(implode(file($this->file)));
        if(file_exists($this->file)) unlink($this->file);
        imagejpeg($img, $this->file, 100);
    }
}

如果我将{3}上的[]替换为''，我会收到相同的错误消息，但在第24行。如果我将[$data]替换为$data我再次获得相同的错误消息，但现在在第89行。如果我用[]替换该行上的''，该功能只会将文件的版权标记更改为2而不是2015 Erik Edgren }。

我该怎么做才能解决这个问题？