Need help with coding for a forum that adds numbers

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February 25th, 2013, 05:29 PM

newbie1234

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Need help with coding for a forum that adds numbers

I need help with coding a page that has two fields so when you put a number in each one and press a button that says add, the output is the answer. almost like its a calculator

This is the code I have so far:

<?php

/*

*/
?>

<!doctype html>
<html lang="eng">
<head>
<meta charset="utf-8">
<title>Add</title>
</head>

<body>
<?php
$value1 = $_POST['value1'];
$value2 = $_POST['value2'];
?>

<body style="background-color:lightgrey;">
<div id="header">
<h1>Add</h1>
<hr>
</div>

<div id="content">

<form name="frmInput" action="add.php" method="post">
<p>Number 1: <input type="text" name="strUserText" value="" maxlength="100" size="50"></p>
<p>Number 2: <input type="text" name="strUserText" value="" maxlength="100" size="50"></p>
<p><input type='submit' name='btnSubmit' value='Add'></p>
</form>
</div>

</body>

</html>

I am totally lost please help. much appreciated thnks in advance!

February 25th, 2013, 05:43 PM

Nanomech

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Hi there,

Try this:

PHP Code:


		
			
<?php

/*

Name: Brittany Hafer



*/



if(isset($_POST['value1']))

{

    $num1 = intval($_POST['value1']);

    $num2 = intval($_POST['value2']);



    $answer = $num1 + $num2;

}

?>

<!doctype html>

<html lang="eng">

<head>

<meta charset="utf-8">

<title>Add</title>

</head>



<body style="background-color:lightgrey;">

<div id="header">

    <h1>Add</h1>

    <hr />

</div>



<div id="content">

    <form name="frmInput" action="add.php" method="post">

        <p>Number 1: <input type="text" name="value1" maxlength="100" size="50"></p>

        <p>Number 2: <input type="text" name="value2" maxlength="100" size="50"></p>

        <p><input type='submit' name='btnSubmit' value='Add'></p>

    </form>



<?php if(isset($answer)){print($answer);} ?>

</div>



<div id="footer">

    <hr />

    <cite>Created for MIS3501, Temple University, February 2013</cite>

</div>



</body>



</html>

When retrieving the values from an <input> in PHP, you need to use the value of the <input>s 'name' attribute within the $_POST superglobal.

For example, if you have <input type="text" name="number1" />

You need to retrieve it like: $_POST['number1'];

Hope this helps you.

Kind regards,

NM.

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Last edited by Nanomech : February 25th, 2013 at 05:50 PM.

February 25th, 2013, 06:03 PM

newbie1234

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IT did not work :/

February 25th, 2013, 07:01 PM

Nanomech

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What is the error you are getting?

Add the code above the doctype to the add.php file.

Regards,

NM.

February 26th, 2013, 08:36 AM

newbie1234

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Never Mind, it works! Thank you so much for your kindness and help.

have a good day!

February 26th, 2013, 09:11 AM

Triple_Nothing

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Sorry to toss a note in at the end here, but if you've some free time, you may be more interested in doing this via Javascript. This will avoid submitting the page every single time, and process it live on the client-side.

February 26th, 2013, 09:41 AM

newbie1234

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Never Mind, it works! Thank you so much for your kindness and help.

have a good day!

February 27th, 2013, 10:39 AM

newbie1234

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Quote:

Originally Posted by Triple_Nothing

Hey Triple_Nothing- perfectly acceptable question. I found my self asking the same thing, and would prefer to do it that way. However-If it is a school assignment and the instructions said we were not allowed to use javascript -___-

February 27th, 2013, 10:41 AM

newbie1234

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Quote:

Originally Posted by Nanomech

What is the error you are getting?

Add the code above the doctype to the add.php file.

Regards,

NM.

hey sorry to bother you with a bunch of questions but I have one last one. How can I alter the code so the answer output states the answer but with each number. so if the user puts 1 and 2 and clicks add, the output would be 1 plus 2 = 3

#10

February 27th, 2013, 11:20 AM

ManiacDan

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PHP Code:


		
			
if(isset($_POST['value1'])) 

{ 

    $num1 = intval($_POST['value1']); 

    $num2 = intval($_POST['value2']); 



    $answer = "{$num1} + {$num2} = " . strval($num1 + $num2); 

}

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#11

February 28th, 2013, 09:11 AM

Nanomech

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Hi Dan that's interesting.

If we concatenate an int value to a string should we always use the strval() function?

Kind regards,

NM.

#12

February 28th, 2013, 09:41 AM

ManiacDan

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Eh. It's not really necessary, but has the same effect:

PHP Code:


		
			
 $answer = "{$num1} + {$num2} = " . strval($num1 + $num2);  

    $answer = "{$num1} + {$num2} = " . ($num1 + $num2);  

    $answer = "{$num1} + {$num2} = " . (string)($num1 + $num2);

Those are all the same. However this:

PHP Code:


		
			
 $answer = "{$num1} + {$num2} = " . $num1 + $num2;

Produces different output. Run it and try to find out why:

PHP Code:


		
			
 $num1 = 3; 

$num2 = 7;



echo "{$num1} + {$num2} = " . strval($num1 + $num2); 

echo "\n"; 

echo "{$num1} + {$num2} = " . ($num1 + $num2);   

echo "\n";

echo "{$num1} + {$num2} = " . (string)($num1 + $num2); 

echo "\n";

echo  "{$num1} + {$num2} = " . $num1 + $num2; 

echo "\n";

The reason I wrote strval is because OP is new (and hopefully trying to actually learn rather than have us do her homework for her all semester) and strval() is the most explicit way of indicating that I wanted the string value of the sum to concatenate onto the string.

Comments on this post

Nanomech agrees: Thank you for explaining that! I've never even looked at that string on php.net and I've browsed the
String functions god knows how many times! n1

#13

February 28th, 2013, 03:58 PM

Triple_Nothing

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Sorry to be slightly off-topic, but in the echos you defined, ManiacDan, is there reason/use to place the variables within curly brackets? { }

#14

February 28th, 2013, 05:55 PM

E-Oreo

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Quote:

Sorry to be slightly off-topic, but in the echos you defined, ManiacDan, is there reason/use to place the variables within curly brackets? { }

In this case, no.

However, if the variables were arrays or objects, then yes.

Using the curly brackets makes it more clear that substitution is occurring.

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#15

March 1st, 2013, 07:57 AM

ManiacDan

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Omitting the curly braces in this particular instance won't break the code, but curly braces are always recommended when you're using variables. Not only does it make your code explicit, but it also allows code editors to highlight the code better and it prevents you from making a mistake like:

PHP Code:


		
			
 $item = "hammer";

$qty = 4;

echo "You purchased $qty $items";

Further, curly braces are the only way to get certain kinds of variable interpolation to work properly. You can include $object->calls() inside strings, as well as $complex['array'][$access], both of which are best to enclose in curly braces.

The manual page on complex string parsing has more.

Need help with coding for a forum that adds numbers

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