The “Form Expression Parser” enables you to parse and calculate custom result variables based on a user’s form field input and private declared variables. The custom result variables will be parsed upon form submission and readily available to you making it possible to store them in a database or other container or take appropriated action depending on the values of the result variables.
Simply add one or more textfields or textareas to your existing form, add your custom result expressions and be on your way. The expression parser can handle simple numbers, defined variables, posted form field values, mathematical expressions such as +, -, * and /, boolean expression and if-statements. Negative numbers are not a problem either!
Use this useful tool if you need to calculate indexes or do calculations on form submitted data. Integration is easy with only one necessary PHP file and only 4 lines to handle the PHP process. On the HTML side you only add one hidden textarea field.