How to get echo to return equation?

Question

I am trying to create a small form which adds certain amounts from an html form The code is found below

HTML Page-->

<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content ="width=device-width,initial-scale=1,user scalable=yes" />
<title>NMAWS Form</title>
<style type="text/css">
div#container
{
   width: 800px;
   position: relative;
   margin-top: 0px;
   margin-left: auto;
   margin-right: auto;
   text-align: left;
}
</style>
<style type="text/css">
body
{
   text-align: center;
   margin: 0;
   background-color: #FFFFFF;
   color: #000000;
}
</style>

</head>
<body>
<form method="post" attribute="post" action="calcsubmit.php">
<br>
<b>Name:<br>
<input type="text" id="name" name="name"><br><br>
Email:<br>
<input type="text" id="email" name="email"><br><br>
Cell Number:<br>
<input type="text" id="cell" name="cell"><br>

<p>Number of people in home:<br/>
<select name="occupants" id="occupants" style="width:100px"><option value="1">1</option><option value="2">2</option><option value="3">3</option><option value="4">4</option>  <option value="5">5</option>  <option value="6">6</option>  <option value="7">7</option>  <option value="8">8</option>  <option value="9">9</option><option value="10">10</option></select></p>

<p>How much do you spend on<br>bottled water each week?<br/>
<select name="water" id="water" style="width:100px"><option value="5">$0 to $5</option><option value="10">$5 to $10</option><option value="15">$10 to $15</option><option value="20">$15 to $20</option><option value="25">$20 to $25</option></select></p>

<p>How many loads of laundry<br>do you do each week?<br/>
<select name="laundry" id="laundry" style="width:100px"><option value="1">1</option><option value="2">2</option><option value="3">3</option>    <option value="4">4</option>  <option value="5">5</option>  <option value="6">6</option>  <option value="7">7</option>  <option value="8">8</option>  <option value="9">9</option><option value="10">10</option></select></p>

<p></p>
<button type="submit" name="answer" id="answer" value="answer" style="width:100px; height:100px;"><font size='4'>Calculate Savings</font></button>
</form>
</body>
</html>

PHP page--->

<html>
<head>
<meta charset="utf-8">
<title>Savings</title>
</head>
<body>
<p>Savings are: 
<?php
if($_POST["answer"])
{
echo "$water + $laundry + $occupants";
}
?>
</p> 
</body>
</html>

The result is always + +, the php isnt even attempting to do the equation I am really not seeing what is wrong here

Should be $_POST['water'], $_POST['laundry'] and so on at least. — raina77ow, Sep 29 '15 at 23:48
its just a sample, the completed project is much more advanced than just adding these values — Koden, Sep 30 '15 at 01:57

cameronjonesweb · Answer 1 · 2015-09-29T23:56:50.903

1

You haven't declared your variables anywhere. You're probably looking for the $_POSTed variables.

If you want to return the equation:

<?php
if($_POST["answer"])
{
echo $_POST['water'] . ' + ' . $_POST['laundry'] . ' + ' . $_POST['occupants'];
}
?>

or if you want to return the answer

<?php
if($_POST["answer"])
{
echo $_POST['water'] + $_POST['laundry'] + $_POST['occupants'];
}
?>

edited Sep 29 '15 at 23:56

answered Sep 29 '15 at 23:49

cameronjonesweb

2,435
3
25
37

Thanks for all the answers, I got it working – Koden Sep 30 '15 at 00:01
that's an expression, not an equation :p – I wrestled a bear once. Sep 30 '15 at 00:04

score 0 · Answer 2 · answered Sep 29 '15 at 23:49

0

Specifically on your question. To get the sum of values. You need to lose the quotes

echo $water + $laundry + $occupants;

Now, overall. There are a few points i'd like to mention. You are using $_POST, so on your secondary page. You need to reference the array by:

echo $_POST['water'] + $_POST['laundry'] + $_POST['occupants'];

Second:

I would not use if ($_POST['answer']). Instead i'd:

if (isset($_POST)){ 

echo $_POST['water'] + $_POST['laundry'] + $_POST['occupants'];

}

answered Sep 29 '15 at 23:49

Daryl Gill

5,464
9
36
69

I wouldn't mind knowing the reason for the down vote? – Daryl Gill Sep 29 '15 at 23:54
It wasn't me, but your first answer, without edition wasn't helpful. Since it was still wrong. – Marcos Casagrande Sep 29 '15 at 23:55
idk, it's a perfectly valid answer. +1 – I wrestled a bear once. Sep 29 '15 at 23:55
oh, well there you go, that's why. – I wrestled a bear once. Sep 29 '15 at 23:56
although.. you shouldn't just `isset($_POST)` as $_POST is often set when you wouldn't expect it to. you shuold definitely check for a specific index. – I wrestled a bear once. Sep 30 '15 at 00:05

Marcos Casagrande · Answer 3 · 2015-09-29T23:57:12.300

0

Loose the quotes "" and $water, $laundy, $occupant are not defined, you should access those values through $_POST instead

<?php
if($_POST["answer"]){ 
  //this will sum the three values.
  echo $_POST["water"] + $_POST["laundry"] + $_POST["occupants"];;
}
?>

edited Sep 29 '15 at 23:57

answered Sep 29 '15 at 23:51

Marcos Casagrande

37,983
8
84
98

How to get echo to return equation?

3 Answers3