从$ _SESSION获取变量会引发错误

Question

在将$_SESSION['var']传递给函数时，如果$_SESSION['var']未设置，我会收到通知：

Notice: Undefined index: var in scripname.php on line 49

是否有更安全的方法来获取$_SESSION['var']，如果0未设置，这会给我$_SESSION['var']？

提前谢谢!!

Answer 1

$var = isset($_SESSION['var']) ? $_SESSION['var'] : 0

Answer 2

if (isset($_SESSION['var']))
{
    echo "session is set";
}
else
{
    echo "session is not set";
}

Answer 3

if (isset($_SESSION['var'])){
    // Do something
}

Answer 4

if(!array_key_exists('var',$_SESSION))
{
    $var = 0;
}
else
{
    $var = $_SESSION['var'];
}

Answer 5

使用

if(isset($_SESSION['var']))
    // do

Answer 6

怎么样：

$var = @$_SESSION['var'];