How to Split a mathematical expression on operators as delimiters, while keeping them in the result?

Question

I need to split an expression like

a+b-c*d/e 

and get a, b, c, d, e sepe

Answer 1

Besides the split approach, you could also use java.util.StringTokenizer:

 String myString = "a+b-c*d/e";

 List operatorList = new ArrayList();
 List operandList = new ArrayList();
 StringTokenizer st = new StringTokenizer(myString, "+-*/", true);
 while (st.hasMoreTokens()) {
    String token = st.nextToken();

    if ("+-/*".contains(token)) {
       operatorList.add(token);
    } else {
       operandList.add(token);
    }
 }

 System.out.println("Operators:" + operatorList);
 System.out.println("Operands:" + operandList);

Result:

Operators:[+, -, *, /]
Operands:[a, b, c, d, e]