Request Priority

A program can choose which request source should win when several sources contain a value.

request_priority.php

<?php
$preferred = ;
$_GET["mode"] = "query";
$_POST["mode"] = "form";
$_COOKIE["mode"] = "stored";

if ($preferred === "post") {
    $mode = $_POST["mode"];
} elseif ($preferred === "cookie") {
    $mode = $_COOKIE["mode"];
} else {
    $mode = $_GET["mode"];
}

echo "preferred=" . $preferred . "\n";
echo "mode=" . $mode . "\n";

<?php
$preferred = ;
$_GET["mode"] = "query";
$_POST["mode"] = "form";
$_COOKIE["mode"] = "stored";

if ($preferred === "post") {
    $mode = $_POST["mode"];
} elseif ($preferred === "cookie") {
    $mode = $_COOKIE["mode"];
} else {
    $mode = $_GET["mode"];
}

echo "preferred=" . $preferred . "\n";
echo "mode=" . $mode . "\n";

<?php
$preferred = ;
$_GET["mode"] = "query";
$_POST["mode"] = "form";
$_COOKIE["mode"] = "stored";

if ($preferred === "post") {
    $mode = $_POST["mode"];
} elseif ($preferred === "cookie") {
    $mode = $_COOKIE["mode"];
} else {
    $mode = $_GET["mode"];
}

echo "preferred=" . $preferred . "\n";
echo "mode=" . $mode . "\n";

explicit source order Choosing an order explicitly is clearer than assuming every request source has the same meaning.