Calculator.java

/**
 * Assignment 4 Q2
 *
 */

/**
 * Student Name: Rup Gautam
 * Student No: 3091289
 */

import java.util.Scanner;


public class Calculator {

  public static void main(String[] args) {
    // An equation with +, -, /, *
    String EquationExp;
    System.out.print("Please enter math Expression: ");
    Scanner kb = new Scanner(System.in);
    EquationExp = kb.nextLine();

    int another = computeEquation(EquationExp);
    System.out.println(another);
  }

  static int computeEquation(String equation) {
    int result = 0;
    String Minus = equation.replace("-", "+-");
    String[] Plus = Minus.split("\\+");

    for (String multiply : Plus) {
      String[] Multiply = multiply.split("\\*");
      int multiplyResult = 1; //
      for (String operand : Multiply) {

        if (operand.contains("/")) {
          String[] division = operand.split("\\/");
          int dividend = Integer.parseInt(division[0]);
          for (int i = 1; i < division.length; i++) {
            dividend /= Integer.parseInt(division[i]);
          }
          multiplyResult *= dividend;
        } else {
          multiplyResult *= Integer.parseInt(operand);
        }
      }
      result += multiplyResult;
    }

    return result;
  }
}