Question

在以下代码中，如何在此语句之外访问$ uname？

 $uname = '';
if ($row['ulogo'] == '1'){
    $ulogo = '../images/varsity logos/witsLogo.jpg';
    $uname = 'Wits';
    echo $uname;
    } else if ($row['ulogo'] == '2'){
        $ulogo = '../images/varsity logos/UJ.png';
    $uname = 'University of Johannessburg';
    echo $uname;
    } 
    echo $uname;

解释你的downvote是否存在。

Answer 1

在if块之外初始化$ uname：

$uname = '';
if ($row['ulogo'] == '1'){
    $ulogo = '../images/varsity logos/witsLogo.jpg';
    $uname = 'Wits';
    echo $uname;
    } else if ($row['ulogo'] == '2'){
        $ulogo = '../images/varsity logos/UJ.png';
    $uname = 'University of Johannessburg';
    echo $uname;
} 
echo $uname;

Answer 2

我不是一个PHP的人，所以如果我错了就纠正我......但要访问$ uname，在if语句之外你必须在if语句之外声明它，所以它在if之外的范围内声明。现在，$ uname只在if语句的范围内，一旦你离开if语句，变量就不再存在了。

Answer 3

如果$ulogo不是$uname或$row['ulogo']，您会注意到未定义的变量1和2。

试试这个：

if ($row['ulogo'] == '1')
{
    $ulogo = '../images/varsity logos/witsLogo.jpg';
    $uname = 'Wits';
}
elseif ($row['ulogo'] == '2')
{
    $ulogo = '../images/varsity logos/UJ.png';
    $uname = 'University of Johannessburg';
} 
else
{
    $ulogo = '../images/varsity logos/noimage.png';
    $uname = NULL;
}

echo $ulogo;
echo $uname;

或

$logo   = '../images/varsity logos/noimage.png';
$uname  = NULL;

if ($row['ulogo'] == '1')
{
    $ulogo = '../images/varsity logos/witsLogo.jpg';
    $uname = 'Wits';
}
elseif ($row['ulogo'] == '2')
{
    $ulogo = '../images/varsity logos/UJ.png';
    $uname = 'University of Johannessburg';
} 

echo $ulogo;
echo $uname;

Answer 4

首先定义全局变量

$ uname ='';   if（$ row ['ulogo'] =='1'）{

$ ulogo ='../ images / varsity logos / witsLogo.jpg';

$ uname ='Wits';

echo $ uname;

}   否则if（$ row ['ulogo'] =='2'）{
   $ulogo = '../images/varsity logos/UJ.png';
$ uname ='约翰内斯堡大学';

echo $ uname;   }

echo $ uname;

Answer 5

您的准则正在运作。我举了一个例子，这是匹配

$row = 1; //temp variable

if ($row == '1'){
    $uname = 'Wits';
} else if ($row == '2'){
    $uname = 'University of Johannessburg';
} 

echo $uname;

Answer 6

上面的答案是正确的，我只是想我会添加另一种方式 -

在返回例如

的函数内定义if语句

function define_username() {
    if ($row['ulogo'] == '1'){
       $ulogo = '../images/varsity logos/witsLogo.jpg';
       $uname = 'Wits';
    } else if ($row['ulogo'] == '2'){
       $ulogo = '../images/varsity logos/UJ.png';
       $uname = 'University of Johannessburg';
    };
    return $uname;
};

echo define_username();

如何访问if语句之外的变量

6 个答案: