Adding

[zheka007]

Hello. I am a beginner in PHP. Can you please assist me. I need to create a script to add two number together. The numbers should come from a web form (HTML) and be sent to the PHP script. The PHP script shoud then add the two numbers together and display the result. Thank you very much in advance!!!

[Ken2k7]

Are you asking someone to help you with this or make it for you?

[zheka007]

if you could please, i have no clue how to do this. I need it for my website. Thank you very much, I really appreciate it

[corbin]

Sounds like homework to me.  If it is, people on forums generally prefer for people to be upfront about something being homework.

 

 

Anyway, the goal of this forum is to help people, not do things for people.  (Well, the freelancing section is all about doing things for people, but chances are, you don't want to pay someone for something this simple.)

 

 

You will want to read a tutorial on $_POST and basic PHP syntax.

 

 

Here are a couple of links:

 

 

http://www.tizag.com/phpT/

http://www.tizag.com/phpT/postget.php

http://www.w3schools.com/php/php_post.asp

[Ken2k7]

zheka007 - I hope you realize that this is for *HELP* not requests.

 

Here's a basic outline (not all complete).

 

something.html

<!-- some HTML -->

<form method="post" action="something.php">
    Number 1: <input type="text" name="num1" /><br />
    Number 2: <input type="text" name="num2" />
</form>

<!-- some more HTML -->

 

something.php

<?php
// check PHP version if it has filter_input() function. If not, use superglobals.
$num1 = filter_input(INPUT_POST, 'num1', FILTER_VALIDATE_INT);
$num2 = filter_input(INPUT_POST, 'num2', FILTER_VALIDATE_INT);
$num1 = empty($num1)? filter_input(INPUT_POST, 'num1', FILTER_VALIDATE_FLOAT);
$num2 = empty($num2)? filter_input(INPUT_POST, 'num2', FILTER_VALIDATE_FLOAT);
if (empty($num1)) die("The first input value is not a number.");
if (empty($num2)) die("The second input value is not a number.");
echo $num1 + $num2;

 

Again, finish the rest yourself.

[Daniel0]

$left = $leftOrig = (int) $_POST['num1'];
$right = $rightOrig = (int) $_POST['num2'];

$c = $r = 0;

for ($t = PHP_INT_MAX; (bool) $t; $t >>= 1) 
{
$r <<= 1;
$r |= ($left ^ $right ^ $c) & 1;
$c = (($left | $right) & $c | $left & $right) & 1;
$left >>= 1;
$right >>= 1;
}

for ($t = PHP_INT_MAX, $c = ~$t; (bool) $t; $t >>= 1)
{
$c <<= 1;
$c |= $r & 1;
$r >>= 1;
}

echo "{$leftOrig} + {$rightOrig} = {$c}";

[premiso]

Pay attention in class, read the chapter, and more importantly....TRY IT YOURSELF FIRST.

 

PS: Daniel, that is the best bit of PHP Code I have ever seen written. That would definitely get me an A on this homework assignment if I turned it in!

[Ken2k7]

Daniel0, that is awesome!

 

zheka007 - If I were you now, I wouldn't pay attention to Daniel0's code. It'll just confuse the heck out of you. But if you want to read up on how his code works, learn about binary and bit shift.

[Mark Baker]

And just for luck, subtraction using Daniel's method:

 

$left = $leftOrig = (int) $_POST['num1'];
$right = $rightOrig = (int) $_POST['num2'];

$right = PHP_INT_MAX ^ $right -1;

$c = $r = 0;

for ($t = PHP_INT_MAX; (bool) $t; $t >>= 1)
{
$r <<= 1;
$r |= ($left ^ $right ^ $c) & 1;
$c = (($left | $right) & $c | $left & $right) & 1;
$left >>= 1;
$right >>= 1;
}

for ($t = PHP_INT_MAX, $c = ~$t; (bool) $t; $t >>= 1)
{
$c <<= 1;
$c |= $r & 1;
$r >>= 1;
}

echo "{$leftOrig} - {$rightOrig} = {$c}";

 

Some of us remember using two's complement

[Mark Baker]

Could also use

$right ^= PHP_INT_MAX;
$right++;

instead of

$right = PHP_INT_MAX ^ $right -1;

[zheka007]

Guys! Thank you very much. You are all awesome!!!