regex for simple math equation

Question

I want to recognize integers or decimals and the four simple operations, broken into tokens I can\'t get the decimal to work, can you please help?

My reg is

Answer 1

It may works for you:

expression = "2.7 + 3 * (1 + 2)";
String expRegString = "\\d+(\\.\\d+)*|\\(\\d+(\\.\\d+)*[\\+\\-\\*\\/]\\d+(\\.\\d+)*\\)";