package sa.edu.yuc;

import java.util.Scanner; import java.util.Stack;

public class Evaluate {

public static void main(String[] args) { Stack operandStack = new Stack(); Stack operatorStack = new Stack(); operatorStack.push('#'); Scanner io = new Scanner(System.in); System.out.print("Enter an expression: "); String input = io.next(); int len = input.length(); for (int i = 0; i < len; i++) { //System.out.print(input.charAt(i)); char symbol = input.charAt(i); if (!isOperator(symbol)) { int n = Integer.parseInt(""+symbol); operandStack.push(n); } else { char poppedOperator = operatorStack.pop(); if (prec(symbol) > prec(poppedOperator)) { operatorStack.push(poppedOperator); operatorStack.push(symbol); } else { int b = operandStack.pop(); int a = operandStack.pop(); if (poppedOperator == '*') { operandStack.push(a * b); } else if (poppedOperator == '/') { operandStack.push(a / b); } else if (poppedOperator == '+') { operandStack.push(a + b); } else if (poppedOperator == '-') { operandStack.push(a - b); } else { //we will deal with it in future } operatorStack.push(symbol); } } } //end of for loop char poppedOperator = operatorStack.pop(); while (poppedOperator != '#') { int b = operandStack.pop(); int a = operandStack.pop(); if (poppedOperator == '*') { operandStack.push(a * b); } else if (poppedOperator == '/') { operandStack.push(a / b); } else if (poppedOperator == '+') { operandStack.push(a + b); } else if (poppedOperator == '-') { operandStack.push(a - b); } else { //we will deal with it in future } poppedOperator = operatorStack.pop(); } System.out.println("Result = " + operandStack.pop()); } private static int prec(char ch) { if (ch == '*' || ch == '/') return 10; else if (ch == '+' || ch == '-') return 5; else if (ch == '#') return 1; else return 0; } private static boolean isOperator(char ch) { if (ch == '+' || ch == '-' || ch == '*' || ch == '/') return true; return false; }

}

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Questions1:

3*4-2

It can only handle single digit operands and no spaces are allowed within the expression. The operators are limited to +, - * and /.

In this Exercise, we want you to extend the given program in such a manner that it could handle decimal numbers, Or Reminder (%) e.g.

2.5 * 4.0 1.5 * 2.0

OR

5 - 2 * 4 % 16

*just apdate on this code*