ok i have a huge problem...everytime i access a protected variable outside the class where it was declared in it gives me the error message of
"object reference not set to an instance of an object"...if i access it in the same class as i declared it in it doesnt give me the error...so probably the problem is in the inhereting of the variable from the class to another class....heres the code
Memory2.cs
Code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace SML
{
class Memory2
{
protected int[] memory;
/*** REGISTERS ***/
protected int accumulator;
protected int programCounter;
protected int instructionRegister;
protected int operationCode;
protected int operand;
public void Memory()
{
Initialize();
}
public void Initialize()
{
int index = 0;
memory = new int[100];
try
{
for (; index < 100; index++)
{
memory[index] = 0;
}
}
catch(Exception e){
Console.WriteLine("Message: "+e.ToString());
}
}
public void Dump()
{
int i = 0,dummy = 0, dummyAccum = 0;
Console.WriteLine("REGISTERS:");
if (accumulator >= 0)
{
if (accumulator.ToString().Length == 1)
Console.WriteLine("Accumulator: \t +000" + accumulator);
else if (accumulator.ToString().Length == 2)
Console.WriteLine("Accumulator: \t +00" + accumulator);
else if (accumulator.ToString().Length == 3)
Console.WriteLine("Accumulator: \t +0" + accumulator);
else
Console.WriteLine("Accumulator: \t +" + accumulator);
}
else
{
dummyAccum = Math.Abs(accumulator);
if (dummyAccum.ToString().Length == 1)
Console.WriteLine("Accumulator: \t -000" + dummyAccum);
else if (dummyAccum.ToString().Length == 2)
Console.WriteLine("Accumulator: \t -00" + dummyAccum);
else if (dummyAccum.ToString().Length == 3)
Console.WriteLine("Accumulator: \t -0" + dummyAccum);
else
Console.WriteLine("Accumulator: \t -" + dummyAccum);
}
if(programCounter.ToString().Length == 1)
Console.WriteLine("Program Counter: \t 0" + programCounter);
else
Console.WriteLine("Program Counter: \t " + programCounter);
if (instructionRegister >= 0)
{
if (instructionRegister.ToString().Length == 1)
Console.WriteLine("Instruction Register: +000" + instructionRegister);
else if (instructionRegister.ToString().Length == 2)
Console.WriteLine("Instruction Register: +00" + instructionRegister);
else if (instructionRegister.ToString().Length == 3)
Console.WriteLine("Instruction Register: +0" + instructionRegister);
else
Console.WriteLine("Instruction Register: +" + instructionRegister);
}
else
{
instructionRegister = Math.Abs(instructionRegister);
if (instructionRegister.ToString().Length == 1)
Console.WriteLine("Instruction Register: -000" + instructionRegister);
else if (instructionRegister.ToString().Length == 2)
Console.WriteLine("Instruction Register: -00" + instructionRegister);
else if (instructionRegister.ToString().Length == 3)
Console.WriteLine("Instruction Register: -0" + instructionRegister);
else
Console.WriteLine("Instruction Register: -" + instructionRegister);
}
if(operationCode.ToString().Length == 1)
Console.WriteLine("Operation Code: \t 0"+ operationCode);
else
Console.WriteLine("Operation Code: \t " + operationCode);
if(operand.ToString().Length == 1)
Console.WriteLine("Operand: \t\t 0"+ operand);
else
Console.WriteLine("Operand: \t\t " + operand);
Console.WriteLine("\nMEMORY: ");
Console.Write(" 0 1 2 3 4 5 6 7 8 9\n");
for (i = 0;i<100 ;i++)
{
if (memory[i] >= 0)
{
displayMemoryNumber(i);
if (memory[i].ToString().Length == 1)
Console.Write("+000" + memory[i] + " ");
else if (memory[i].ToString().Length == 2)
Console.Write("+00" + memory[i] + " ");
else if (memory[i].ToString().Length == 3)
Console.Write("+0" + memory[i] + " ");
else
Console.Write("+" + memory[i] + " ");
}
else
{
dummy = Math.Abs(memory[i]);
if (dummy.ToString().Length == 1)
Console.Write("-000" + dummy + " ");
else if (dummy.ToString().Length == 2)
Console.Write("-00" + dummy + " ");
else if (dummy.ToString().Length == 3)
Console.Write("-0" + dummy + " ");
else
Console.Write("-" + dummy + " ");
}
}
}
private void displayMemoryNumber(int index)
{
switch(index)
{
case 0: Console.SetCursorPosition(0, 9);
Console.Write(index + " ");
break;
case 10: Console.SetCursorPosition(0, 10);
Console.Write(index + " ");
break;
case 20: Console.SetCursorPosition(0, 11);
Console.Write(index + " ");
break;
case 30: Console.SetCursorPosition(0, 12);
Console.Write(index + " ");
break;
case 40: Console.SetCursorPosition(0, 13);
Console.Write(index + " ");
break;
case 50: Console.SetCursorPosition(0, 14);
Console.Write(index + " ");
break;
case 60: Console.SetCursorPosition(0, 15);
Console.Write(index + " ");
break;
case 70: Console.SetCursorPosition(0, 16);
Console.Write(index + " ");
break;
case 80: Console.SetCursorPosition(0, 17);
Console.Write(index + " ");
break;
case 90: Console.SetCursorPosition(0, 18);
Console.Write(index + " ");
break;
}
}
}
}
decode.cs
Code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace SML
{
class decode:Memory2
{
public void LoadtoMemory(int address, int value)
{
//check if the memory address is valid
if ((address >= 0) && (address <= 99))
memory[address] = value;
else
Console.Write("\nError: Invalid address at " + address + ".\n");
}
public void display()
{
programCounter = 0;
for (; programCounter <= 99; programCounter++)
{
if (memory[programCounter] == 4300)
{
Console.WriteLine("\t\t\t*******Program Ended*******");
break;
}
else
{
Console.Clear();
operationCode = memory[programCounter] / 100;
operand = memory[programCounter] % 100;
instructionRegister = memory[programCounter];
Dump();
decode2();
Console.ReadLine();
}
}
}
public void display2()
{
programCounter = 0;
for (; programCounter <= 99; programCounter++)
{
if (memory[programCounter] == 4300)
{
Console.WriteLine("\t\t\t*******Program Ended*******");
break;
}
else
{
Console.Clear();
operationCode = memory[programCounter] / 100;
operand = memory[programCounter] % 100;
//Dump();
decode2();
}
}
}
public void decode2()
{
if (operationCode == 10)
{
read();
}
else if (operationCode == 11)
{
write();
}
else if (operationCode == 20)
{
load();
}
else if (operationCode == 21)
{
store();
}
if (operationCode == 30)
{
add();
}
if (operationCode == 31)
{
subtract();
}
if (operationCode == 32)
{
multiply();
}
if (operationCode == 33)
{
divide();
}
if (operationCode == 40)
{
}
if (operationCode == 41)
{
branchneg();
}
if (operationCode == 42)
{
}
if (operationCode == 43)
{
}
}
public void branch()
{
programCounter = operand - 1;
}
public void branchneg()
{
if (accumulator < 0)
{
programCounter = operand - 1;
}
}
public void branchzero()
{
if (accumulator == 0)
{
programCounter = operand - 1;
}
}
public void read()
{
Console.Write("INPUT: ");
memory[operand] = int.Parse(Console.ReadLine());
}
public void write()
{
Console.WriteLine(memory[operand]);
}
public void load()
{
accumulator = memory[operand];
}
public void store()
{
memory[operand] = accumulator;
}
public void add()
{
accumulator = accumulator + memory[operand];
}
public void subtract()
{
accumulator = accumulator - memory[operand];
}
public void multiply()
{
accumulator = accumulator * memory[operand];
}
public void divide()
{
accumulator = accumulator / memory[operand];
}
}
}
pls help guyz...every reply would be appreciated...nosebleed na kaayo ko ani gamay na lang kuwang
C# Problem: Protected Variable
Reply With Quote
Posting Permissions
