trying to get my c++ arithmetic calculator to detect multiple periods(AKA illegal decimals 1.2.3)

[WoodyWoo]

so I was able to get my code to detect characters and not allow them, but now I need it to detect multiple .'s if that makes sense, such as allow 1.23 but not 1.2.3, Please I need help as this is due in 3 hours and even my professors are too busy with other shit to help a student.

#include <iostream>
#include <cstdlib>
#include <time.h>
#include <math.h>
#include <errno.h>   


using namespace std;

const double MAXRANGE = pow(2.0, 16.0); // 65536
const double MINRANGE = -pow(2.0, 16.0);

bool validDouble(const char* argument)
{
    return atof(argument);
}

int main(int argc, char* argv[])
{
    

    char z;

    bool isARealDouble = true;
    
    if (argc == 3)
    {
        z = 0;
    }
    else if (argc == 4)
    {
        z = argv[3][0];
    }
    else if (argc < 3)
    {
        cout << "P" << endl;
        return 0;
    }
    else if (argc > 4)
    {
        cout << "P" << endl;
        return 0;
    }

    if ((z == 'a') || (z == 's') || (z == 'm') || (z == 'd') || (z == 'p') || (z == 0))
    {


        if (z == 0)
        {
            float h;
            float x = atof(argv[1]);
            float y = atof(argv[2]);
            if (x <= MINRANGE)
            {
                cout << "R" << endl;
                return 0;
            }
            else if (x >= MAXRANGE)
            {
                cout << "R" << endl;
                return 0;
            }
            if (y <= MINRANGE)
            {
                cout << "R" << endl;
                return 0;
            }
            else if (y >= MAXRANGE)
            {
                cout << "R" << endl;
                return 0;
            }

            for (int i = 1; i < argc; i++)
            {
                isARealDouble = true;

                for (int j = 0; j < strlen(argv[i]); j++)
                {
                
                    cout << argv[i][j] << " ";
                    if (isdigit(argv[i][j]) || argv[i][j] == '.')
                    {   
                        isARealDouble = true;
                                            }
                    else
                    {
                    isARealDouble = false;  
                    cout << "X" << endl;
                    return 0;
                    }
                        
                }
                
                
            }
            if (isARealDouble)
            {
                h = x + y;
                cout << h << endl;
                return 0;
            }
        }

        
    }
    

    return 0;
}

Ignore the if((z == 'a') || (z == 's') ... ect) stuff i left out some code that isnt important.

[Mateyyy]

You could have a counter that you increment every time you detect a '.' (or 46 on the ASCII table). If the counter is higher than 1, so you have more '.', then you don't allow it.

Hopefully I actually understood what you're trying to do and this makes sense.

[WoodyWoo]

14 minutes ago, Mateyyy said:

You could have a counter that you increment every time you detect a '.' (or 46 on the ASCII table). If the counter is higher than 1, so you have more '.', then you don't allow it.

Hopefully I actually understood what you're trying to do and this makes sense.

#include <iostream>
#include <cstdlib>
#include <time.h>
#include <math.h>
#include <errno.h>   


using namespace std;

const double MAXRANGE = pow(2.0, 16.0); // 65536
const double MINRANGE = -pow(2.0, 16.0);

bool validDouble(const char* argument)
{
	return atof(argument);
}

int main(int argc, char* argv[])
{
	
	char z;

	bool isARealDouble = true;
	
	if (argc == 3)
	{
		z = 0;
	}
	else if (argc == 4)
	{
		z = argv[3][0];
	}
	else if (argc < 3)
	{
		cout << "P" << endl;
		return 0;
	}
	else if (argc > 4)
	{
		cout << "P" << endl;
		return 0;
	}

	if ((z == 'a') || (z == 's') || (z == 'm') || (z == 'd') || (z == 'p') || (z == 0))
	{


		if (z == 0)
		{
			float h;
			float x = atof(argv[1]);
			float y = atof(argv[2]);
			if (x <= MINRANGE)
			{
				cout << "R" << endl;
				return 0;
			}
			else if (x >= MAXRANGE)
			{
				cout << "R" << endl;
				return 0;
			}
			if (y <= MINRANGE)
			{
				cout << "R" << endl;
				return 0;
			}
			else if (y >= MAXRANGE)
			{
				cout << "R" << endl;
				return 0;
			}


			for (int i = 1; i < argc; i++)
			{
				isARealDouble = true;

				for (int j = 0; j < strlen(argv[i]); j++)
				{
					
					cout << argv[i][j] << " ";
					if (isdigit(argv[i][j]) || argv[i][j] == '.')
					{	
						isARealDouble = true;
                      	int w = 0
						if (argv[i][j] == '.')
						{
							w =+ 1;
							if (w > 1)
							{
								cout << "X" << endl;
								return 0;
							}
						}
					}
					else
					{
					isARealDouble = false;	
					cout << "X" << endl;
					return 0;
					}
						
				}
				
				
			}
			if (isARealDouble)
			{
				h = x + y;
				cout << h << endl;
				return 0;
			}
		}

	}
	

	return 0;
}

I added a counter but it isnt working it resets w back to zero, I dont know how to keep the value.

[Mateyyy]

6 minutes ago, WoodyWoo said:

I added a counter but it isnt working it resets w back to zero, I dont know how to keep the value.

Try adding in "int w = 0;" before the j loop.

for (int i = 1; i < argc; i++)
{
	int w = 0;
    isARealDouble = true;
    
    for (int j = 0; j < strlen(argv[i]); j++);
    ...
    

 

[WoodyWoo]

3 minutes ago, Mateyyy said:

Try adding in "int w = 0;" before the j loop.

for (int i = 1; i < argc; i++)
{
	int w = 0;
    isARealDouble = true;
    
    for (int j = 0; j < strlen(argv[i]); j++);
    ...
    

 

That was it thank you so much

 

[mariushm]

You should also look into finite state machines and think how pocket calculators do these things when they use 4 bit or 8 bit microcontrollers with maybe tens of bytes of memory

 

Some links to read : 

 

https://medium.com/@rvunabandi/making-a-calculator-in-javascript-64193ea6a492

https://www.codinglawyer.io/posts/build-javascript-calculator

https://www.clear.rice.edu/comp212/06-spring/labs/13/

https://gist.github.com/freshwater/3805768