JavaScript function to add a string of numbers

Question

Not sure how to word this and so am not having much luck in Google searches...

I need to calculate a value for a string of numbers.

Example. A user types in "1.00 + 2.00 - 0.50" into a text field. The function should be able to take that string and calculate the result to return $2.50.

Anyone have a way to do this in their bag of tricks?

Answer 1

If it's actually a mathematical operation you may just use eval, not sure that's what you want though :

document.write(eval("1.00 + 2.00 - 0.50"));

Answer 2

Theo T's answer looks like the most straightforward way, but if you need to write your own simple parser, you can start by splitting the string and looking for your operators in the output.

Answer 3

New there had to be a simple super way to do it. That's exactly what I need, thanks!