PHP Switch statement comparison issues - php

Question

so I have a variable called multiplier that contains a certain value depending on what the user registered with. What I am trying to write here is
If multiplier is equal to "sedentary" then give it the value of $sedmultiplier
If multiplier is equal to "lightly" then give it the value of $lightmultiplier
Im stuck on this, can't seem to figure out how this would be written.
switch ($multiplier==) {
case "sedentary":
$multiplier=$sedmultiplier;
break;
case "lightly":
$multiplier=$lightmultiplier;
break;
case "moderately":
$multiplier=$modmultiplier;
break;
case "very":
$multiplier=$verymultiplier;
break;
case "extremely":
$multiplier=$extrememultiplier;
break;
default:
multiplier==0;
}

Answer 1

Replace $multiplier== with $multiplier and your code should work.
Like this :
switch ($multiplier)
{
case "sedentary":
$multiplier=$sedmultiplier;
break;
case "lightly":
$multiplier=$lightmultiplier;
break;
case "moderately":
$multiplier=$modmultiplier;
break;
case "very":
$multiplier=$verymultiplier;
break;
case "extremely":
$multiplier=$extrememultiplier;
break;
default:
$multiplier==0;
}

Answer 2

Just like #jeroen suggested, I would set the multipliers as an array instead. This way you can reuse them and add/remove multipliers more easily.
// Create the array with name => multiplier
$multipliers = [
"sedentary" => $sedmultiplier,
"lightly" => $lightmultiplier,
"moderately" => $modmultiplier,
"very" => $verymultiplier,
"extremely" => $extrememultiplier,
// ... just add more here, if needed...
];
// Check if we have a key with the current name.
// If we do, return the value, otherwise return 0 as default.
$multiplier = array_key_exists($multiplier, $multipliers)
? $multipliers[$multiplier]
: 0;