Question

Java Code: I am using the code below but it will not compile.

PROGRAM:

using System;
//import java.util.Scanner;
//Create the class that would perform the simulation.
public class Simulator
{
   public static void main(String[] args)
   {
       //list of SML instructions
       const int READ_INS = 10;
       const int WRITE_INS = 11;
       const int LOAD_INS = 20;
       const int STORE_INS = 21;
       const int ADD_INS = 30;
       const int SUBTRACT_INS = 31;
       const int MULTIPLY_INS = 32;
       const int DIVIDE_INS = 33;
       const int BRANCH_INS = 40;
       const int BRANCH_NEG_INS = 41;
       const int BRANCH_ZERO_INS = 42;
       const int HALT_INS = 43;
  
   //variabes for storing the instruction and its details.
   int accumulator;
   int instructionCounter;
int op_oprnd;
   int op_Code;
   int instructionRegister;
  
       //simpletron memArray
   int[] memArray;
  
   //number of instructions entered in memArray
   int index = 0;

      /* Method to run the simpletron simulator*/
   }

  

ERROR MESSAGE:

Simulator.java:1: error: class, interface, or enum expected
using System;
^
Simulator.java:9: error: illegal start of expression
const int READ_INS = 10;
^
Simulator.java:10: error: illegal start of expression
const int WRITE_INS = 11;
^
Simulator.java:11: error: illegal start of expression
const int LOAD_INS = 20;
^
Simulator.java:12: error: illegal start of expression
const int STORE_INS = 21;
^
Simulator.java:13: error: illegal start of expression
const int ADD_INS = 30;
^
Simulator.java:14: error: illegal start of expression
const int SUBTRACT_INS = 31;
^
Simulator.java:15: error: illegal start of expression
const int MULTIPLY_INS = 32;
^
Simulator.java:16: error: illegal start of expression
const int DIVIDE_INS = 33;
^
Simulator.java:17: error: illegal start of expression
const int BRANCH_INS = 40;
^
Simulator.java:18: error: illegal start of expression
const int BRANCH_NEG_INS = 41;
^
Simulator.java:19: error: illegal start of expression
const int BRANCH_ZERO_INS = 42;
^
Simulator.java:20: error: illegal start of expression
const int HALT_INS = 43;
^
  

Answer 1

Error details:In java const is not used instead of that final is used.

Below is the code that compiles successfully.

Simulator.java :

import java.util.Scanner;

//Create the class that would perform the simulation.
public class Simulator {
   public static void main(String[] args) {
       // list of SML instructions
       final int READ_INS = 10;
       final int WRITE_INS = 11;
       final int LOAD_INS = 20;
       final int STORE_INS = 21;
       final int ADD_INS = 30;
       final int SUBTRACT_INS = 31;
       final int MULTIPLY_INS = 32;
       final int DIVIDE_INS = 33;
       final int BRANCH_INS = 40;
       final int BRANCH_NEG_INS = 41;
       final int BRANCH_ZERO_INS = 42;
       final int HALT_INS = 43;

       // variabes for storing the instruction and its details.
       int accumulator;
       int instructionCounter;
       int op_oprnd;
       int op_Code;
       int instructionRegister;

       // simpletron memArray
       int[] memArray;

       // number of instructions entered in memArray
       int index = 0;

       /* Method to run the simpletron simulator */
   }
}