Very simple PHP addition problem

Question

I think I have been looking at this for too long. Why is this code printing 'no', it should be printing 'yes' shouldn't it? I've tried it on PHP 5.3 and PHP 5.2 and both print 'no'.

<?php

$total = 14.05;
$var1 = 0;
$var2 = 0.11;
$var3 = 13.94;

if(($var1 + $var2 + $var3) == $total)
{
    echo 'yes';
}
else
{
    echo 'no';
}

?>

Answer 1

See Comparing floating point numbers.

This doesn't work because floating point numbers are not represented exactly. A small rounding error is enough for the equality operator to fail.