public static void main(String args[]) { String str1 = "a+b"; String str2 = "a-b"; Map<String, Integer> map = new HashMap<String, Integer>(5); map.put("a", 3); map.put("b", 4); Calculator cal = new Calculator(str2); System.out.println(str2 + cal.run(map)); }
public static void main(String[] args) { Calculator calculator = new Calculator(); calculator.addOperation(new Plus(calculator, "+")); calculator.run(); }