## Shizuo

lest say I have a inputbox in html and I want to compute the answer to ..hmm lets say

1 + 2 - 1 * 6 + 8 / 2

want is the basic function for this? you can just teach me the basics, or advice something . I'm new to PHP

## sv3tli0

in real if you just set it to calculate this directly it will do it :)
php is making math calculations so it will calculate this for you
try:

``````<?php
\$var=1 + 2 - 1 * 6 + 8 / 2;
echo \$var; ?>``````

## Shizuo

oh. thanks man.

I have another question , how about I add a square root added to the above example like

1 + 2 - 1 * 6 + 8 / 2 + √2

should I make anther function for the sqr root?

## sv3tli0

correct name for it is: sqrt
sqrt(9)=3

## Shizuo

ok I get it, but lets say I have button for sqrt which will add the sqrt symbol in the input area . but how do I exactly compute the sqrt if inside the input is the symbol.

## diafol

you can't use the symbol.
you just use sqrt().
If you want a visual, use the html character number for the symbol, but don't use this in the calculation.
alternatively, use pow(\$number,0.5), but that isn't an improvement.

You can't read the input box and get php to evaluate it, you'll need to use substitution and possibly reorganization to get it to work.

## Shizuo

ah yes , it just echoed my inputs . how do I make it compute?

## diafol

You can't read the input box and get php to evaluate it

unless input box has readable php format, which it probably won't.