Variable Problem

You guys will be sick of me by now haha oh well.

Aim: Mathematical Sum
Problem: I'm pulling out the sum type e.g. + - * / but I also need to use the same variable to work out the sum

Code:

if($_POST['Submit']!=''){
$a = $_POST['a'];
$b = $_POST['b'];
$c = $_POST['c'];
$d = $_POST['d'];
$ansa = $_POST['ansa'];






//calculations

$resulta = (int)($a.$b) * (int)($c.$d);
echo "Your answer was: $ansa<br>";
if ( $ansa == $resulta ) {
$total = $total+1;

	echo "<font color=green><b>CORRECT!</b></font>";
} 
else {
$total = $total+0;
	echo "<font color=red><b>INCORRECT!</b><br></font>";
echo "The correct answer was: $resulta <BR>";
}
}

PHP:

At the moment the sum type is * so it's not random, I'm using word.txt to pull them at random, here's the form code:

<form name="calc" method="post" >
<table align="center" width="200" style="border:2px solid black;">
<tr>
<td width="100"><font color="white" size="25px">.</font><input name="a" value="<?php echo "$random_number5";?>" type="text" id="variable_a" style="width:30px;font-size:35px;font-weight:bold;background:white;border:none;"></td>
<td><font color="white" size="25px">.</font><input name="b" value="<?php echo "$random_number6";?>" type="text" id="variable_b" style="width:30px;font-size:35px;font-weight:bold;background:white;border:none;"></td></tr>
<tr>
<td width="100"><font size="20px"><?php echo "$word";?></font><input name="c" value="<?php echo "$random_number7";?>" type="text" id="variable_a" style="width:30px;font-size:35px;font-weight:bold;background:white;border:none;"></td>
<td><font color="white" size="25px">.</font><input name="d" value="<?php echo "$random_number8";?>" type="text" id="variable_b" style="width:30px;font-size:35px;font-weight:bold;background:white;border:none;"></td></tr>
<tr> <td colspan="3" align="center"><input name="ansa" type="text" id="variable_b" ></td></tr>
<tr><td colspan="3" align="center"><input type="submit" name="Submit" value="Calculate" style="border:2px solid black;padding:2px;"></td></tr>
</table>

</form>

PHP:

Where the sum is being calculated I only get errors when I use:

$resulta = (int)($a.$b) $word (int)($c.$d);

instead of:

$resulta = (int)($a.$b) * (int)($c.$d);

Is there any way around this or am I just fighting a losing battle?

Thanks for your help guys!

 

FYI, if you're trying to add $a to $b , use + , as . is used to join two strings. For example if you typed 4 for a, and 5 for b, and 6 for c, and 7 for d. Your code is basically saying 45 * 67, was that the intended behavior?

You might need to do your math on one line, and join text on another.

 

I've changed the random number to display as 1 instead of 2.

I was getting it to output the number that should be 56 as 5 and 6 instead but I've changed it to the whole number.

$resulta = $a * $b;
echo "<h1>$a * $b = $resulta<br></h1>";

I think I was just being stupid, I could just use an IF statement to say
IF ($word == +) {
$resulta = $a + $b
}
IF ($word == -) {
$resulta = $a + $b
}

So on and so forth.

Thanks for you advise.

 

Okay so I'm struggling here to.

I only got errors when I fitted an if statement because I was using a variable.

So I decided to test it by just outputting if it is + echo this is addition etc.

Here's the code:

<?php
if (($word) == '+') {
echo "This is an addition sum";
}

if (($word) == '-') {
echo "This is a subtraction sum";
}
?>

PHP:

The words.txt looks like so:

+
-

The PHP will output correctly if it is a subtraction but it will not output if it's an addition very weird.

Any ideas?

 

I've only been doing PHP for a few months and I'm teaching myself as I go, but thanks for your help here's What I came up with:

<?php

$sum_type = $word;

?>
<?php echo "$sum_type";?>

PHP:

But I still need to be able to use $sum_type in my calculation here:

$resulta = $a * $b;

Instead of * I need to echo $sum_type there but I just get dreaded Parse error: syntax error, unexpected T_VARIABLE.

Please please please somebody help meeee.

Thanks.

 

I would suggest you to use preg_match instead of == operator and match the word and operator you are trying to compare

Hope this will help you

Thanks!!

 

Though if the word is a valid operand, he may just have to throw the entire line into an eval() function (evaluates a string as if it were a formated php line).

 

Is there another way I can do it. At the moment I'm storing + - / * on seperate lines in a .txt file and that's how I'm calling them by random, but the trouble is working out the sum, as the + - / * seem a lot harder than just the variable.

As I said I'm not an expert I'm very much a noob so forgive me.