Question

Here is the PHP im working with:

Below values from a database:

$quote = 49;
$add_amp = 0;
$con_array = "3,2,1";


function calcAddAmp($mul)
{
    $add_amp = $add_amp + $mul*($quote);

}


$con_array = explode(",", $con);

for($i = 0; $i < count($con_array); $i++) { 
    switch ($fun) {
        case 1:
            calcAddAmp(.01);
            break;
        case 2:
            calcAddAmp(.05);
            break;
        case 3:
            calcAddAmp(.02);
            break;
        case 4:
            calcAddAmp(.09);
            break;
    }
}



$quote = $quote + $add_amp;

The issue is seen here:

echo $add_amp;

$add_amp returns 0, which makes $quote the same value as before, 49.

echo $quote;

I’m sure I am just writing this function incorrectly, but I can’t find where I went wrong.

Answer 1

Variables have function scope. Setting $add_amp inside a function does not automatically modify the variable by the same name outside the function. If you don’t return the value from the function it’s pointless. I’d simplify this whole unnecessary switch/function to this though:

$multipliers = array(1 => .01, 2 => .05, 3 => .02, 4 => .09);

foreach ($con_array as $con) {
    $add_amp += $multipliers[$con] * $quote;
}