检查会话变量是否由其名称的第一部分设置

Question

I know I can check if a session variable exists by doing:

if (isset($_SESSION['variable']))

But would it be possible to check if the session exists by the first part of its name, so for example:

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

returns true for:

if (isset($_SESSION['variable'])) 

or

if (isset($_SESSION['varsomethingelse']))

Answer 1

You can simply loop through your $_SESSION and check for existance of "var" with strpos in your sessions key:

    $_SESSION = ['variable' => 1, 'variablesomething' => 2, 'variablesomethingelse' => 3,'else' => 3]; // just for testing, you don't need this replace
    foreach ($_SESSION as $key => $value) {
        if (strpos($key, 'var') > -1)
        {
            echo 'This key in your Session is set: ' . $key . '<br>';
        }

    }