Question

I am a newbie of PHP coding, and want to do a simple math example, d=(a+b)/c.

The values of a and b will be submitted by the user from a webpage containing PHP form.
The value of c is predefined in the PHP page.

When the user click “submit” in this webpage.
I expect to get the result of d in the bottom of the same webpage.

Any example code will be greatly appreciated.

Answer 1

<form method="POST" action="">
<input type="hidden" id="c" name="c" value="10" />
<label for="a">a: </label>
<input type="text" id="a" name="a" /> <br />
<label for="b">b: </label>
<input type="text" id="b" name="b" />
<input type="submit" />
</form>
<br />

<?php
if (isset($_POST["a"]) && isset($_POST["b"]) && isset($_POST["c"])) {
    if (is_numeric($_POST["a"]) && is_numeric($_POST["b"]) && is_numeric($_POST["c"])) {
        $d = ($_POST["a"] + $_POST["b"])/$_POST["c"];
        echo "d = ". $d;
    } else {
        echo "all values must be numeric!"
    }
}
?>