going through a php excercise...confused need help

[TakenAwy1]

Hi Everyone, I'm new here...

I'm going through a simple PHP exercise, but can't seem to figure it out...

Suppose a Can of Soup costs 5 dollars and a Chocolate Bar costs 3 dollars. I have 78 dollars on me.

I need to write a php function that can calculate how many cans of soups and chocolate bars I can get, starting with cans of soup first.

I can do it in my head...It's 14 Cans of Soup and 2 Chocolate Bars, leaving me with 2 dollars.

Does anyone have an idea on where to start? Thanks!

[amax]

thats a nice little question for us beginners. I too am just starting to get the hang of functions after diving straight into some basic MySQL. Heres what I have so far:

<?php

$soup_price =  5;
$soup_counter = 0;
$choc_price =  3;
$choc_counter = 0;

echo "<table border=\"1\" align=\"center\">";
echo "<tr><th>Quantity of soup </th><th>Quantity of choc</th></tr>";
while ( $soup_counter <= 78 &&  $choc_counter <= 78 ) {
	echo "<tr><td>";
	echo $soup_counter;
	echo "</td><td>";
	echo $choc_counter;
	echo "</td></tr>";
	$soup_counter = $soup_counter + 5;
	$choc_counter = $choc_counter + 3;
}
echo "</table>";

?>

Hope this helps a little to start with, your turn 🙂

[amax]

I could actually be totally wrong in my approach, maybe a while loop isnt the right tool in this case..I was hoping I could count the number of times the while loop executed but realise now I dont know how to do that . sorry. maybe it has given you an idea

[rikmoncur]

wouldn't it be 15 cans of soup, 1 choc bar and no change?

[rikmoncur]

Your example:
For $78.00 You get 15 tins of soup, totalling $75.00
(78 / 5 = 15 remainder 3) use floor() to round down the number of tins, then subtract the total (5 * 15) from your starting price.
This leaves $3.00
Chocolate costs $3.00 a bar, so you can buy 1 bar with $0.00 change.
(soup remainder / 3 = 0)

Another example:
For $79.50 You get 15 tins of soup, costing $75.00
(78 / 5 = 15 remainder 4.5)
This leaves $4.50
Chocolate costs $3.00 a bar, so you can buy 1 bar with $1.50 change
(soup remainder / 3 = 1 remainder 1.5)

Assign the numbers to variables, then it's just arithmetic.
Look at money_format() to format the currency.
You could also look at the modulus arithmetic operator but it only seems to work on whole numbers - it strips the decimals before dividing.

[TakenAwy1]

thank you all for the help.

ps. i meant to say 15 cans and chocolate bar in my example

[NogDog]

One approach:

<?php
function exactChange($price1, $price2, $cash)
{
   if($price1 > $cash or $price2 > $cash)
   {
      user_error("Not enough cash");
      return false;
   }
   $found = false;
   for($qty = floor($cash / $price1); $qty >= 0; $qty--)
   {
      $rem = $cash - $qty * $price1;
      if($rem % $price2 == 0)
      {
         return (array($qty, $rem / $price2));
      }
   }
   user_error("No no-change combination found");
   return false;
}

if(is_array($result = exactChange(5, 3, 78)))
{
   echo "Soup: $result[0], candy: $result[1]";
}

[rikmoncur]

This was my script. I like how nogdog got it all in a function tho.

$money = '79.5';
$soup = '5';
$choc = 3;


$tins =  floor($money / $soup);
$tins_remainder = $money - ($tins*$soup);
echo "For $" .money_format('%i', $money). " You get " .$tins. " tins of soup, costing $". money_format('%i', $tins*$soup) .  "<br />";

echo "This leaves $" . money_format('%i', $tins_remainder) . "<br />";

$chocbars = floor($tins_remainder / $choc);
$choc_remainder = $tins_remainder - $choc;
echo "Chocolate costs $".money_format('%i', $choc)." a bar, so you can buy ". $chocbars . " bar with $" . money_format('%i', $choc_remainder) . " change.";

[rikmoncur]

Wrapping it up as a function was easier than I thought! here it is:

function pricer($money, $soup, $choc)
{ 
$tins =  floor($money / $soup);
$tins_remainder = $money - ($tins*$soup);
echo "For $" .money_format('%i', $money). " You get " .$tins. " tins of soup, costing $". money_format('%i', $tins*$soup) . " at $". $soup." per tin<br />";

echo "This leaves $" . money_format('%i', $tins_remainder) . "<br />";

$chocbars = floor($tins_remainder / $choc);
$choc_remainder = $tins_remainder - $choc;
echo "Chocolate costs $".money_format('%i', $choc)." a bar, so you can buy ". $chocbars . " bar with $" . money_format('%i', $choc_remainder) . " change.";
}

echo pricer(78, 5, 3); //cash, soup price, choc price

[dalecosp]

rikmoncur;10905254 wrote:

This was my script. I like how nogdog got it all in a function tho.

What I don't like is that his modulo operator was converted to an HTML entity. :queasy:

[Jumanji]

I'm really really confuse how to use the function any help thanks
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