PHP · Theory

Sessions

Theory

44/352

Sessions

A session remembers the user across pages. session_start(); then $_SESSION['user'] = 'Asha'; Next page: session_start(); echo $_SESSION['user']; PHP stores data on the server and sends a cookie with the session id.

session_start() must run before any HTML output. session_destroy() on logout. Don’t store passwords in $_SESSION.

Trap — forgetting session_start(). Trap: session_start after echo.

Exam tip

session_start(); $_SESSION['user']='Asha';

Example

<?php
// Sessions
$scores = [80, 90, 70];
$avg = array_sum($scores) / count($scores);
echo "avg=" . number_format($avg, 1) . "\n";
foreach ($scores as $s) {
  if ($s >= 80) echo "high: $s\n";
}

Sessions: scores array, print avg, then high marks. Say the output.

Short notes

Def$_SESSION is server-side login memory.
Rulesession_start() first. Cookie holds the id.
TrapHTML before session_start.

PHP · Theory

Sessions

← All stacks

Theory

44/352

Sessions

session_start() must run before any HTML output. session_destroy() on logout. Don’t store passwords in $_SESSION.

Trap — forgetting session_start(). Trap: session_start after echo.

Exam tip

session_start(); $_SESSION['user']='Asha';

Example

<?php
// Sessions
$scores = [80, 90, 70];
$avg = array_sum($scores) / count($scores);
echo "avg=" . number_format($avg, 1) . "\n";
foreach ($scores as $s) {
  if ($s >= 80) echo "high: $s\n";
}

Sessions: scores array, print avg, then high marks. Say the output.

Short notes

Def$_SESSION is server-side login memory.
Rulesession_start() first. Cookie holds the id.
TrapHTML before session_start.

Sessions

Example

Short notes

Questions

Sessions

Example

Short notes

Questions