$ _SESSION ['user_id'] is enough to check input in PHP?

Question

When a user logs in to a website, I save user_idto SESSION to check later if the user is logged in or not.

if(!empty($_SESSION['user_id'])){
  ....

Is this enough for security?

Answer 1

This will depend entirely on how this variable goes to the session and how well you manage the session.

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Answer 2

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isset():

function loggedIn()
{
  if (isset($_SESSION['user_id']) && is_numeric($_SESSION['user_id']))
    return true;
  return false;
}

, 0, empty() true!

Answer 3

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Answer 4

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- $_SESSION ['user_id'] = $_GET ['user_id'], : .

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Answer 5

if(!isset($_SESSION($user_id){

, $user_id == 0 then isempty() , , , .

unset($_session_variable_name);

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Answer 6

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