C++ Print A Box Application

Question

I'm currently working on a c++ project that prints a box to the screen based on the user's entered width and height input. I can so far print out the top, bottom, and left side dots on the screen. The only thing i need help with is printing out the far right dots. I've provided a screen shot of the output below the code.

CODE:

#include <iostream>
using namespace std;

int main() 
{
    int width;
    int height;

    //Introduction:
    cout<<"Welcome to the [Draw A Rectangle] program!\n";
    cout<<"This program will draw a rectangle in the application\n";
    cout<<"You will have to enter the width and the height and it will draw   it\n";

    //User enters box width and height:
    cout<<"Please enter a width: ";
    cin>>width;

    cout<<"Please enter a height: ";
    cin>>height;

    //Prints the top dots (horizontal):
    for (int dots; dots <= width; dots++)
    {
        cout<<"*";
    }   

    //Prints the left dots (vertical):
    for (int dots; dots < height; dots++)
    {
        cout<<"*\n";
    }

    //Prints the bottom dots (horizontal):
    for (int dots; dots <= width + 1; dots++)
    {
        cout<<"*";
    }

    //Keeps program running:
    cin.get();
    }

Screenshot:

As you can see the dots are not printing on the far right side and the box is incomplete, and I need this fixed, anything helps, Please!

Answer 1

Based on the width entered, when you insert the left dot, insert an appropriate number of spaces and then the right dot. Put the newline after the right dot.

Answer 2

I had some fun with it:

See IDEOne Link

#include <stdio.h>

int main(void) {
    int height = 10;
    int width = 10;
    int it, in;

    it=width;
    while (it --> 0) putchar('*'); putchar('\n');

    it = height-2;
    while(it --> 0)
    {
        in = width-2;
        putchar('*'); while(in --> 0) putchar(' '); putchar('*'); putchar('\n');
    }

    it=width;
    while (it --> 0) putchar('*'); putchar('\n');
    return 0;
}

Answer 3

Perhaps a simpler version:
(but likely a bit obfuscated to most C programmers)

#include <stdio.h>
void line(char s, int w, char b, char e)
{
                   { putchar(s);    }
    while(w --> 0) { putchar(b);    }
                   { putchar(e);    }
                   { putchar('\n'); }
}

int main(void)
{
    int width  = 10;
    int height =  6;
        width -=  2;
        height-=  2;
                        { line('+', width, '-', '+'); }
    while(height --> 0) { line('|', width, ' ', '|'); }
                        { line('+', width, '-', '+'); }
    return 0;
}

Output

+--------+
|        |
|        |
|        |
|        |
+--------+

Answer 4

This solution may be 5 years late, but does correct the problems with the original program.

It checks that the user input is within acceptable values for the 80x24 output of a standard terminal and that the dimensions are positive. Big values are cropped to the max 80x24 chars and the absolute value of negative numbers entered are used. NOTE: this program does NOT check if non integer values are entered.

Other than the user input verification, this solution rectifies the errors in the original code and uses c++'s std::endl instead of c's \n for a new line.

If you are only interested in the code to print the box look for the code after the comment:

//3. Print the box

---

#include <iostream>
#include <cstdlib>
#include <iomanip>
using namespace std;

int main() 
{
    int width = 0;
    int height = 0;

    // 1. Get User Input
    //Introduction:
    cout << "Welcome to the [Draw A Rectangle] program!" << endl;
    cout << "This program will draw a rectangle in the application" << endl;
    cout << "You will have to enter the width and the height"
         << " and it will draw it" << endl;

    //User enters box width and height:
    cout << "Please enter the width: ";
    cin >> width;

    cout << "Please enter the height: ";
    cin >> height;

    // 2. Verify Validity of User Input
    //      Height Max 24 width max 80 not zero or negative values


    // 2a. check that width is not zero or negative.
    if (width < 1) // zero or negative
    {
        if (width < 0)
        {
            cout << "A rectange must have a positive width [" << width 
                 << "] set to " << abs(width) << "." << endl;

            width = abs(width);
        }
        else // width == zero
        {
            cout << "A rectangle must had a width of 1 or more."
                << " Width [" << width << "] set to 1." << endl;
            width = 1;
        }
    }

    // 2b. check that height is not zero or negative.
    if (height < 1)
    {
        if (height < 0)
        {
             cout << "A rectange must have a positive height [" << height 
            << "] set to " << abs(height) << "." <<endl;

            height = abs(height);

        }
        else // height == zero
        {
            cout << "A rectangle must had a height of 1 or more."
                << " Height [" << height << "] set to 1." << endl;
            height = 1;
        }
    }



    // 2c. Limit to 80x24 chars.
    // The standard vt100 terminal was only 80x24 chars
    // 2c i) check width 80 or less
    if (width > 80)
    {
        cout << "Width must be 80 or less. Width [" << width 
             << "] limited to 80." << endl;
        width = 80;
   }



    // 2c ii) check height 24 or less
    if (height > 24 ) 
    {
        cout << "Height must be 24 or less. Height [" << height 
             << "] limited to 24." << endl;
         height = 24;
   }

    // 3. Print the box 
    //Prints the top dots (horizontal):
    for (int dots = 0; dots < width; dots++)
    {
        cout << "*";
    }   
    
    cout << endl;
    //Prints the left dots (vertical):
    // note first and last row are rows of dots 
    if (height > 1 )
    {
        for (int dots = 0; dots < height-2; dots++) // first row already printed
        {
            cout << setw(1) <<"*";
            if (width > 1 )
            {
                cout << setw(width-1) << right << "*" << endl;
            }
            else
                cout << endl;
        }
        
        //Prints the bottom dots (horizontal):
        for (int dots = 0; dots < width; dots++)
        {
            cout<<"*";
        }
        cout << endl;
    }

    //Keeps program running:
    cin.get();
}

---

Sceenshot

Answer 5

You can output spaces after the vertical line. Here is a modified version of the code to accomplish this task:

//Prints the top dots (horizontal):
for (int dots = 0; dots < width; dots++)
{
    cout<<"*";
}
cout<<endl;


//Prints the left dots (vertical):
for (int dots = 0; dots < height-2; dots++)
{
    cout<<"*";
    for(int i = 0; i < width-2; ++i) cout<<" ";
    cout<<"*"<<endl;
}

//Prints the bottom dots (horizontal):
for (int dots = 0; dots < width; dots++)
{
    cout<<"*";
}