Cannot get functions to execute - php

Question

So if the last function ended up working. And I followed all of your instructions to the T, why is this function not working properly? I've looked over it for an hour, tried rewrite it over and over again and all I get is a 0 or no return.
function marketing () {
$newsold = $_POST['newsold'];
$usedsold = $_POST['usedsold'];
$carsSold = $newsold + $usedsold;
$AdSpend = $carsSold * 275;
echo "You shoud spend roughly $AdSpend per year on advertising";
}
marketing();

Answer 1

You echo the values inside the function:
not:
echo "$autoProfit";
but,
<?php
function autoProfits () {
$usedprofit = 1527;
$newprofit = 800;
$newsold = $_POST['newsold'];
$usedsold = $_POST['usedsold'];
$uprofit = $usedsold * $profitused;
$nprofit = $newsold * $profitnew;
$autoProfit = $uprofit + $nprofit;
}
autoProfits();
?>
Take close att with the curly brace where to be placed.

Answer 2

Several things with your code:
1) By default, a form will post with GET and not POST. So either change your PHP variables to $_GET OR change your form's method to $_POST. I prefer to change the method.
<form action="calc.php" method="POST">
2) You're missing a curly brace on your function:
function makeProfit () {
if ($profit >=0) {
echo "Your company is making a profit.";
} else {
echo "Your company is not making a profit.";
}
}
3) In your function adSpend(), you should invert the line for $carsSold.
4) You have used upper and lower-case characters interchangeably in your variable names ($usedSold vs $usedsold). PHP variables are case-sensitive.
5) The "+" operator when used to combine a string and integer may work, but it would be better not to put integers in quotes.
5b) Using a comma will cause PHP to not recognize your variable as a number, so use $profitUsed = 1527; instead of $profitUsed = "1,527";
6) Your variables at the top of a PHP file are not GLOBAL. You'll either need to convert them to global variables, or (I prefer) send them as parameters to your function. An example of the corrected adSpend():
function adSpend ($newSold = 0, $usedSold = 0) {
$adSpendPerCar = 275;
$carsSold = $newSold + $usedSold;
$adSpend = $carsSold * $adSpendPerCar;
echo $AdSpend;
}
adSpend($newSold, $usedSold);
7) Finally, when you expect an integer from user input, you'd be best to verify that you have an integer. There are a lot of ways to do this, one simple method is to do something like this:
$newSold = intval($_POST['newsold']);
$usedSold = intval($_POST['usedsold']);
Edit Change your variables $profitused for $usedprofit and $profitnew for $newprofit
function autoProfits () {
$usedprofit = 1527;
$newprofit = 800;
$newsold = $_POST['newsold'];
$usedsold = $_POST['usedsold'];
$uprofit = $usedsold * $usedprofit;
$nprofit = $newsold * $newprofit;
$autoProfit = $uprofit + $nprofit;
echo $autoProfit;
}

Answer 3

function makeProfit () {
if ($profit >=0) {
echo "Your company is making a profit.";
} else {
echo "Your company is not making a profit.";
}
}
This function is missing the last '}' (curly bracket)
But you should also be sure when calling adSpend(), that the variables you're trying to access is set, else you won't get anything out of it.
Since you've made that setup, then you should be calling the functions right after you've set all the variables, for anything to work.

Answer 4

You're using undefined variables on the products. You defined $usedprofit and $newprofit but you're multiplying $profitused and $profitnew. Since they're not defined, PHP assumes they're 0.