有没有理由我没有看到,为什么这不行？
$journalName = $_POST['journalName'];
$journalName = str_replace(' ','_',$journalName);
$_SESSION['journalName'] = $journalName;
echo $_SESSION['journalName'];
我建议您使用它,因为它将检查单个和多个空白空间(由Lucas Green提出).
$journalName = preg_replace('/\s+/',$journalName);
代替：
$journalName = str_replace(' ',$journalName);
