I have to write a program in C++ for class that uses nested loops to display a hollow rectangle with stars ( * ). I can display a whole rectangle with the following code: --------------- // This will ask the user to enter the height of the rectangle. cout << "Please enter the height of the rectangle." << endl; cin >> rec_height; // This will ask the user to enter the width of the rectangle. cout << "Please enter the width of the rectangle." << endl; cin >> rec_width; // This will pass the height and width of the rectangle to the function. draw_rectangle = Rectangle(rec_height, rec_width); /* This function will accept two integers, the height and width, and will draw a rectangle of that height and width.*/ int Rectangle(int a, int b) { int rh = 1; int rw = 1; for (rh = 1; rh <= a; rh++) { for (rw = 1; rw <= b; rw++) cout << "*"; cout << endl; } return 0; } ---------------- A hollow rectangle would look something like this: **** * * * * **** I tried modifying the code: --------------- int HollowRectangle(int a, int b) { int rh = 1; int rw = 1; for (rh = 1; (rh == 1) || (rh == a); rh++) { for (rw = 1; rw <= b; rw++) { cout << "*"; } cout << endl; } for (rh = 2; (rh > 1) & (rh < a); rh++) { for (rw = 1; rw <= b; rw++) { cout << " "; } cout << endl; } return 0; } --------------- But it only displays one line of stars and then all blank lines. I was wondering if anyone had any ideas or knew what part of the code I should try modifying. I tried a bunch of other modifications to the code, but they just caused an infinite loop of "*". Basically, I just need the first and last lines to have "*" all across, and the middle lines just have a "*" at the first and last column of each line. Thank you very much for any help.

Here you go: #include <conio> #include <iostream> using namespace std; void HollowRectangle(int Height, int Width) {     // we need to build the rectangle from the top to the bottom     // so we will start with the rows as the outer loop     for(int row=0;row<Height;row++)     {         // now check to see if we are top row or bottom row         if(row == 0 || row+1 == Height)         {             // fill in the columns with asterisks             for(int column=0;column<Width;column++)             {                 cout << "*";             }         }         else         {             for(int column=0;column<Width;column++)             {                 // we always put an asterisk in first column                 // and last column                 if(column == 0 || column+1 == Width)                     cout << "*";                 else                     cout << " ";             }         }         cout << endl;     } } void main(void) {     HollowRectangle(10,10);     getch(); } The problem i see with your attempt is that you are attempting to print out your asterisks first then your spaces second. You can't do that, they have to be done together. Chi They mostly come at night...mostly

for(int row=0;row<Height;row++) {    // Always output a first column asterisk    cout << "*";    // Loop thru inner cols    for(int column=1;column<Width-1;column++)    {       // Output * or space       cout << (row == 0 || row+1 == Height) ? "*" : " ";    }    //Always output an end column asterisk    cout << "*"; } cout << endl; Be sure to come back and let us know if our suggestions helped!

I forgot to comment. I took CHs code and combined it a bit. I didn't test but it should work with a little or no tweaking. The idea is that for the inner loop, you always output an asterisk in the first and last columns, so I have a cout << "*"; surrounding my inner loop. THen I change the inner loop to count from 1 to width-1, rather than 0 to width, so the inner loop goes thru all columns except for the left and rightmost. Then the only question is whether the inner loop should be outputting * or spaces. An even more efficient version would be: char mychar; for(int row=0;row<Height;row++) {    // Always output a first column asterisk    cout << "*";    // Set char to output    mychar = (row == 0 || row+1 == Height) ? "*" : " ";    // Loop thru inner cols    for(int column=1;column<Width-1;column++)    {       // Output * or space       cout << mychar;    }    //Always output an end column asterisk    cout << "*"; } cout << endl; Be sure to come back and let us know if our suggestions helped!

Thanks so much everyone! Don, your version is probably more efficient, but we didn't really learn 'char' yet, and I don't know if he wants us to do it that way. I integrated Chi's code into my program, and it works fine. I knew that I had to do the asteriks and spaces together and not separate, but I wasn't quite sure how. Thanks again everyone.

Also, Don's doesnt work right. (sorry don but i tested yours and although it is more obfuscated it needs a few changes to work right) for(int row=0;row<Height;row++) {    // Always output a first column asterisk    cout << "*";    // Loop thru inner cols    for(int column=1;column<Width-1;column++)    {       // Output * or space       // don's original outputs ones and zeros preceeded and followed by *s       // cout << (row == 0 || row+1 == Height) ? "*" : " ";       //You have to modify it so that it prints the characters and not the result of the comparison       cout << ((row == 0 || row+1 == Height) ? "*" : " "); // added parens    }    //Always output an end column asterisk    // don's code forgot to add endl each time:    //cout << "*";    // i simply added an endl    cout << "*" << endl; } cout << endl; and the char one wont work because you cannot convert a char * to a char, so you have to modify it like this: char mychar; for(int row=0;row<Height;row++) {     // Always output a first column asterisk     cout << "*";     // Set char to output     // don's has same issue with 1's and zero's insead of *s     // as well as generating error "cannot convert char * to char     mychar = (row == 0 || row+1 == Height) ? "*" : " ";     // mine forces the conversion and adds parens to send * instead of 1 and 0     mychar = *((row == 0 || row+1 == Height) ? "*" : " ");     // Loop thru inner cols     for(int column=1;column<Width-1;column++)     {         // Output * or space         cout << mychar;     }     //Always output an end column asterisk     // again, don forgot the endl:     cout << "*";     // i simply added an endl     cout << "*" << endl; } cout << endl; So you would have to know about pointers as well as chars. Nice try tho, Don. It is definitely more obfuscated and optimized. Chi They mostly come at night...mostly