X^2 to Math.pow(x,2)

Question

I am writing a program that takes an argument equation and calculates a Riemann sum. I've got the bulk of the coding written. I have no problem converting any type of trig functions in the argument to their proper string representations of the java.lang.Math class and method, ie if user enters sin(x)/cos(x), the program converts it to a string of Math.sin(x)/Math.cos(x). However, when I try to convert x^2 (x squared) to Math.pow(x,2), the computer just leaves it as it is. This is the code i've tried so far:
args[0] = sin(x)/cos(x)  // user input at command line
args[0].replaceAll("sin","Math\u002Esin");
args[0].replaceAll("cos","Math\u002Esin");However, when I try the same with x^2 as input, even with the unicode instead of a carat, the output is still just x^2. Any idea how I can get a string of x^2 converted to Math.pow(x,2) ?

Answer 1

then you're going to need a regular expression
something
like.replaceAll("(.*)x\\^([0-9]).*(.*)", "\\1
Math.pow(x, \\2) \\3")
Solved the problem with
for(int i = 0; i < 10000; i++){
   s = s.replaceAll(String.format("x\\^"+i),String.format("Math\u002Epow("+i+")") );
}covers integer exponents up to 10000, and barely noticeable increase in calculation time. thanks to all for the help!