PHP · Theory

Cookies

Theory

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Cookies

A cookie is a small string stored in the browser. setcookie('theme', 'dark', time()+86400, '/'); then $_COOKIE['theme']. Use for theme or ‘remember me’ token — not the raw password.

HttpOnly cookies are harder for JS to steal. Expiry in the past deletes a cookie.

Trap — setcookie after HTML started. Trap: huge data in cookies — use sessions.

Exam tip

setcookie then $_COOKIE. Sessions for login state.

Example

<?php
// Cookies
$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";
}

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

Short notes

DefCookie = small data in the browser.
Rulesetcookie before HTML. Not for passwords.
TrapOutput before setcookie.

PHP · Theory

Cookies

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Theory

43/352

Cookies

A cookie is a small string stored in the browser. setcookie('theme', 'dark', time()+86400, '/'); then $_COOKIE['theme']. Use for theme or ‘remember me’ token — not the raw password.

HttpOnly cookies are harder for JS to steal. Expiry in the past deletes a cookie.

Trap — setcookie after HTML started. Trap: huge data in cookies — use sessions.

Exam tip

setcookie then $_COOKIE. Sessions for login state.

Example

<?php
// Cookies
$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";
}

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

Short notes

DefCookie = small data in the browser.
Rulesetcookie before HTML. Not for passwords.
TrapOutput before setcookie.

Cookies

Example

Short notes

Questions

Cookies

Example

Short notes

Questions