mutiple math operations in a single output

[wannabeengr]

im trying to do a math calculation that involves multiple math operation ex((a+b)*(sin(a)/sin(b)) something like this but whenever i execute the code its giving me 3 answers this is the code hoping you could help me it very urgent though

#include <iostream.h>
#include <math.h>
#include <string.h>




int nVar = 0;
char varName[50];
double varValue[50];

double getValue(char ch);
void setValue(char ch, double d);

int main()
{
	cout << "This program enables the user to perform Math Functions such as fabs, sqrt, pow, log, log10, sin cos, tan, asin, acos, atan, atan2, sinh, cosh, tanh, ceil, floor, mod. Just input a character(a - z ) followed by an equal sign and the numerical value then press enter. Then in the preceding line input the function you want to use followed by a parenthesis and the alpha character then press enter. To quit, type quit then press enter:\n\n\n";

	for(int i = 0; i < 50; i++)
	{
		varName[i] = '(';
	}

	char ch;
	char input[6];
	double operand1;
	double operand2;
	double res;

	while(1)
	{
		cout << ">>";

		cin >> ch;
		
	
		if(ch =='q'|| ch =='Q')
		{
			break;
		}
		
		if(ch =='quit')
		{
			break;
		}
		

		input[0] = ch;

		operand1 = getValue(ch);

		cin >> ch;
		input[1] = ch;
		if(ch == '=')
		{
			cin >> operand1;

			setValue(input[0], operand1);

			cout << input[0] << "=\n\n\n\t" <<operand1 << "\n";

		}
		else
		{
			switch(ch)
			{
			case'+':

				cin >> ch;

				operand2 = getValue(ch);

				res = operand1 + operand2;

				cout << "ans=\n\n\n\t" << res << "\n";
				break;

			case'-':

				cin >> ch;

				operand2 = getValue(ch);

				res = operand1 - operand2;

				cout << "ans=\n\n\n\t" << res << "\n";
				break;

			case'*':

				cin >> ch;

				operand2 = getValue(ch);

				res = operand1 * operand2;

				cout << "ans=\n\n\n\t" << res << "\n";
				break;

			case'/':

				cin >> ch;

				operand2 = getValue(ch);

				res = operand1 / operand2;

				cout << "ans=\n\n\n\t" << res << "\n";
				break;

			default:


				cin >> input[2];
				int i = 3;
				while (ch != '(')
				{
					cin >> ch;
					input [i] = ch;
					i++;
				}
			

				input[i-1] = '\0';

				if(strcmp(input, "sin") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = sin(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";

					cin >> ch;

				}
				
				if(strcmp(input, "cos") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = cos(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";

					cin >> ch;
				}

				if(strcmp(input, "tan") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = tan(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";

					cin >> ch;
				}

				if(strcmp(input, "exp") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = exp(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
				}

				if(strcmp(input, "log") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = log(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
				}

				if(strcmp(input, "pow") == 0)
				{
					cin >> ch;
					
					operand1 = getValue(ch);

					cin >> ch;

					cin >> ch;

					operand2 = getValue(ch);

					res = pow(operand1, operand2);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
				}

				
				if(strcmp(input, "asin") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = asin(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}
				
				if(strcmp(input, "acos") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = acos(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
				}
				
				if(strcmp(input, "atan") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = atan(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}
				
				if(strcmp(input, "fabs") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = fabs(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}
				
				if(strcmp(input, "sqrt") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = sqrt(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}

				if(strcmp(input, "ceil") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = ceil(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}
				
				if(strcmp(input, "sinh") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = sinh(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}
				if(strcmp(input, "cosh") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = cosh(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}
				if(strcmp(input, "tanh") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = tanh(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}

				if(strcmp(input, "fmod") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = fmod(operand1, operand2);

					cout << "ans=\n\n\n\t" << res << "\n";

					cin >> ch;

				}

				if(strcmp(input, "floor") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					res = floor(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
			
				}

				if(strcmp(input, "log10") == 0)
				{
					cin >> ch;

					//cin >> ch;

					operand1 = getValue(ch);

					res = log10(operand1);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
				}
				if(strcmp(input, "atan2") == 0)
				{
					cin >> ch;

					operand1 = getValue(ch);

					cin >> ch;

					cin >> ch;

					res = atan2(operand1, operand2);

					cout << "ans=\n\n\n\t" << res << "\n";
					
					cin >> ch;
				}

				break;
			}
		}
	}
	return 0;
}


double getValue(char ch)
{
	for(int i = 0; i < nVar; i++)
	{
		if(ch == varName[i])
		{
			return varValue[i];
		}
	}
	varName[nVar] = ch;
	varValue[nVar] = 0.0;

	nVar++;
	return 0.0;
}


void setValue(char ch, double d)
{
	for(int i = 0; i <nVar; i++)
	{
		if(ch == varName[i])
		{
			varValue[i] = d;
		}
	}
}

[PanGalactic]

Line breaks, dude...

cout << "some string"
    " that continues"
    " on multiple"
    " lines"

iostream.h has been deprecated for over a decade. What compiler are you using?

[turbozedd]

Try refactoring your program. Make it so that every function does 1 and only 1 thing (including main).

Extract all of the stuff in your if else if into functions. Remove duplication. Then try looking for the bug again.

Also if you use a map for variables you can look them up by name.

[wannabeengr]

im using microsoft visual c++ 6.0 i know its old but thats the one being used in the university so im trying to use the same

could you cite an example how to map the variables and look them up by name?

[firedraco]

std::map<std::string, int> int_map; //this is a bunch of ints with an std::string as a key

int_map["a"] = 2; //"a" key doesn't exist so it gets created
int_map["b"] = 3;
int_map["a"] = 0; //now "a" == 0, "b" == 3 

[S6k9GNh0]

		if(ch == '=')
		{
			cin >> operand1;

			setValue(input[0], operand1);

			cout << input[0] << "=\n\n\n\t" <<operand1 << "\n";

		}

Putting this outside of the switch statement seems pointless to me. If you were to place this in a switch statement, it would work just fine if not the exact same and faster.

				cin >> ch;

				operand2 = getValue(ch);

				res = operand1 * operand2;

				cout << "ans=\n\n\n\t" << res << "\n";
				break;

This also seems strange to me. I would go ahead and place this is a function for code reuse at it's simplest form. You may not want to put all of this in there and make a function that allows more flexibility. For instance, leave out cin >> ch; so the function doesn't require an input.