Int Arguments

This is so great! This is a great board, a lot of helpful people here and I look forward to learning a lot here. I just finished "Teach Yourself C++ in 21 Days", so I'm not a complete newb, but I definately need to learn a lot more. So everyone prepare for my MANY MANY questions!

Heres a question to get things rolling

Code:

---

//  Triangle computation program

#include <iostream>
using namespace std;

int main(int argc, int *argv[])
{
    int a, b, c;
  //cout << argch[0];
  cout << "\n";
  cout << argv[1];
  cout << argv[2];
  cout << argv[3];



  if (argc > 4 || (argc < 4 && argc > 1))
  {
    cout << "Invalid number of sides.\n";
    cout << "Implementation: <filename> sideA sideB sideC\n";
  }

  if (argc == 4)
  {
    a = argv[1];
    b = argv[2];
    c = argv[3];
    cout << "Calculating based on given arguments.\n";
  }


  if(argc == 1)
  {
    cout << "Enter side 1: ";
    cin >> a;
    cout << "Enter side 2: ";
    cin >> b;
    cout << "Enter side 3: ";
    cin >> c;
    cout << "Calculating...\n";
    }

    if ( a == b && a == c && b == c )
      cout << "This is an equilateral Triangle.\n\b";

    if ( (a == b && a !=c) ||
        (a == c && a !=b) ||
        (b == c && b !=a) )
        cout << "This is an isocles Triangle.\n\b";
    if ( ((a*a)+(b*b)== (c*c)) ||
        ((b*b)+(c*c)== (a*a)) ||
        ((c*c)+(a*a)== (b*b)) )
        cout << "This is a right triangle.\n\b";
    else
        cout << "Please check the numbers and try again!\n";

    return 0;
}

---

The only thing I couldn't get to work is for this program to use integers it receives from the command line. How can I get this to work? Thanks.
-Peace

Quote:

---

Originally posted by Scytz0

Code:

---

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

---

---

this should be:

Code:

---

int main( int argc, char *argv[] )
{
//and now you need to parse argv for the arguments...remember
//that arguments are usualy seperated by a flag ( - )
//...so if running a prog with arguments you would have somthin
//like this:
//user~>main -nrows -ncols
....

---

axon

Thanks, I'll try that.

// ** EDIT **

Does this look right?

Code:

---

//  Triangle computation program

#include <iostream>
using namespace std;

int main(int argc, char argv[])
{
    int a, b, c;
  //cout << argch[0];
  cout << "\n";
  cout << argv[1];
  cout << argv[2];
  cout << argv[3];



  if (argc > 4 || (argc < 4 && argc > 1))
  {
    cout << "Invalid number of sides.\n";
    cout << "Implementation: <filename> sideA sideB sideC\n";
  }

  if (argc == 4)
  {
    a = argv[1];
    b = argv[2];
    c = argv[3];
    cout << "Calculating based on given arguments.\n";
    cout << a << "\n" << b << "\n" << c << endl;
  }


  if(argc == 1)
  {
    cout << "Enter side 1: ";
    cin >> a;
    cout << "Enter side 2: ";
    cin >> b;
    cout << "Enter side 3: ";
    cin >> c;
    cout << "Calculating...\n";
    }

    if ( a == b && a == c && b == c )
      cout << "This is an equilateral Triangle.\n\b";

    if ( (a == b && a !=c) ||
        (a == c && a !=b) ||
        (b == c && b !=a) )
        cout << "This is an isocles Triangle.\n\b";
    if ( ((a*a)+(b*b)== (c*c)) ||
        ((b*b)+(c*c)== (a*a)) ||
        ((c*c)+(a*a)== (b*b)) )
        cout << "This is a right triangle.\n\b";
    else
        cout << "Please check the numbers and try again!\n";

    return 0;
}

---

This is what I type at the command line

C:\Documents and Settings\admin\Desktop>tri2 -3 -4 -5

and I get this:

8" Calculating based on given arguments.
56
34
0
Please check the numbers and try again!


What am I doing wrong?

axon's advice was correct, but you didn't quite follow it exactly. He said

Quote:

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

---

but you used

Quote:

---

int main( int argc, char argv[] )

---

Once you fix that your code won't work still because you are setting a char array to an int. Since argv is an array of char* objects, that means it is 0 or more char* strings. So argv[0] is a null terminated string, as is argv[1], argv[2] and argv[3] (assuming your example arguments).

I'd suggest using the standard string class to hold those strings, but whichever way you do it you'll have to read up a bit on it to properly save the values as ints.

Could you nudge me in the right direction or give me a hint as to how I would use a string to accomplish this? Thanks.
-Peace

jlou is right..

>>C:\Documents and Settings\admin\Desktop>tri2 -3 -4 -5

if these are your arguments, trace back what happens to them.
argc is set to 4. So the first element of argv is tri2. Anyways, below I'm attaching a prog that parses a command line which I wrote not so long ago...here is what it supposed to do...it does have one bug when your command starts out with an alpha char.

Code:

---

//argument:    main 234aa34  34b  23  3b4
//display:
234
34
34
23
3
4

---

as you can see the prog seperates the integesr from the characters. each time an char or white space is encoutered go to new line.

Code:

---

#include <iostream>
#include <cctype>
#include <cstring>

using namespace std;

int main(int argc, char *argv[])
{
        int a=0; //counter for amount of letters
        char c;

        if ( argc == 1 ) {        //check for amount of arguments
                cout << "\nThere is nothing to parse!\n";
                cout << endl;
        } else {
                for ( int i = 1; i < argc; i++ ) {
                        for ( int j = 0; j < strlen(argv[i]); j++ ){
                                c = argv[i][j];        //step through each string and
                                if ( isdigit(c) ) { //check if value is a digit
                                        if ( a > 0 ) {
                                                cout << endl;
                                                a=0;
                                        }
                                        cout << argv[i][j];// << endl;
                                }else { a++; } //if value is not digit increment a
                        }
                        cout << endl;
                }
        }
        return 0;
}

---

axon

Quote:

---

Originally posted by Scytz0
Could you nudge me in the right direction or give me a hint as to how I would use a string to accomplish this? Thanks.
-Peace

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one word atoi()

do a little search for it. It should also be in your book.