A calculator script consisting of select drop-down lists and counting the final result.

A site user can select a name from each select drop-down list. Each name has a corresponding value, for example, it can be the cost-100 rubles, or the weight-5 kg, etc. Each drop-down list is independent and represents its own characteristic or name of something. Also, within the drop-down lists, related items can be divided into subgroups.

When you click the "Calculate" button, a mathematical calculation is performed using the specified formula. The formula can be any. In this example, all the values obtained from the select drop-down lists are added together. The received amount is displayed in the total column. The contents of all selected items are also displayed.

============ Settings for the select drop-down list calculator

A value of 100
where,
'Value 100' - name of the item.
value= '100' – the value corresponding to this item in the list.

============ Formula for calculating the select drop-down list calculator

sum = val1 + val2 + val3 + val4 + val5;
where
sum – the result of the calculation.
val1 ... val5 – value values for the selected items.

============ Installing the select drop-down list calculator

Insert the calculator in the html code of the page, in the place where you want to display the calculator.

============ Requirements for the select drop down list calculator

Browser, javascript

============ Editing data from select drop-down lists and calculator calculation formulas

With a basic knowledge of html and javascript, you can easily add new drop-down lists and new items inside drop-down lists. To do this, add new lines of code, similar to the existing ones in the example. Then, adjust the calculation formula according to your requirements. Also, for convenience, the javascript code has appropriate comments and suggestions.