在php应该怎样写这样的session代码

Question

等效的php代码
session_start();
$_SESSION['username'] = $_POST['name'];
$_SESSION['userid'] = $_POST['id'];
$_SESSION['entid'] = $_POST['entid'];

Answer 1

等效的php代码
session_start();
$_SESSION['username'] = $_POST['name'];
$_SESSION['userid'] = $_POST['id'];
$_SESSION['entid'] = $_POST['entid'];

Answer 2

<?php
session_start();
$_SESSION['username'] = xxx;
$_SESSION['userid'] = xxx;
$_SESSION['entid'] = xxx;
?>

Answer 3

$_SESSION['username'] = xxx;
用这个形式写，其实都不用session_start()