PHP - session编码和解码

<?php 

    //session编码
    session_start();

    $_SESSION['name'] = 'Jack';
    $_SESSION['sex'] = 'men';

    $envar = session_encode();

    echo $envar;//name|s:4:"Jack";sex|s:3:"men";

    echo '<br/>';

    //session解码
    session_decode($envar);

    echo $_SESSION['name']."-".$_SESSION['sex'];

?>