在PHP中将fraction转换为float

Question

How to convert 1/4 to 0.25 in PHP.

In form I insert number as 1/4. In action page I get the post variable as 1/4. How can I convert this to 0.25. I think in action page this is obtained as string. Thats why it displayed as 1/4. But I need 0.25. How can I do this??

main page

<input type="text" name="a" id="a">

action page

$a = $_POST['a'];
echo $a;  //gives 1/4 but need 0.25

Please help..

Answer 1

You can use a function like this:

<?php

    function calculate_string( $mathString )    {
        $mathString = trim($mathString);
        $mathString = str_replace ('[^0-9\+-\*\/\(\) ]', '', $mathString); 

        $compute = create_function("", "return (" . $mathString . ");" );
        return 0 + $compute();
    }

    echo calculate_string("1/4");


?>

Output:

0.25