PHP 类 - fatal error : Can't use method return value in write context

Question

<?php /* my function class */
class dbFunctions{
public  $dbHost  = "localhost", 
        $dbLogin = "root",
        $dbPwd   = "",
        $dbName  = "forex",
        $mysqli;

/* Create a new mysqli object with database connection parameters */
public function __construct(){
    $this->mysqli = new mysqli($this->dbHost, $this->dbLogin, $this->dbPwd , $this->dbName);
    if(mysqli_connect_errno()) {
        echo "Connection Failed: " . mysqli_connect_errno();
        exit();
    }
}
public function address(){
    if($stmt = $this->mysqli -> prepare("SELECT `email_content` FROM `content` WHERE `content_name`= ? ")) {
        $content = 'address';
        $stmt -> bind_param("s", $content);
        $stmt -> execute();
        $stmt -> bind_result($result);
        $stmt -> fetch();
        $stmt -> close();
        echo $result;
    }
}
}
$obj = new dbFunctions() ;
?>

<!-- MY FOOTER FILE WHERE I CALLED THE FUNCTION-->
     <div id="address">
        <a href="#" style="color:#fff; text-decoration:none;"> Contact Us:</a>
        <?php if(!empty($obj->address())){?><?php $obj->address();?>
        <?php }?>
    </div>

fatal error :无法在第 3 行的 C:\wamp\www\forex\includes\footer.html 的写入上下文中使用方法返回值

请帮我解决这个问题..我搜索了很多但没有找到任何解决方案。

Answer 1

问题出在第 3 行的页脚中:

<?php if(!empty($obj->address())){?><?php $obj->address();?>

来自 PHP 手册:

Prior to PHP 5.5, empty() only supports variables; anything else will result in a parse error. In other words, the following will not work: empty(trim($name)). Instead, use trim($name) == false.

你必须将 $obj->address() 设置到它自己的变量中，并用 empty() 测试这个变量。