C / C++ / MFC

5-Dec-11 8:34

I'm building a pyramid of asterisk with for loop statement:

for (int i = 1, i < 5, i++)
{
for (int j = 1; j <= i, j++)
{
cout << "*";
}
cout << endl;
}

here's is the question: i need another for loop statement to reverse the pyramid. I need it has to do something with the spaces, but could not write one. Since i don't have a database to look at. Could someone hint me in the right direction?

Albert Holguin5-Dec-11 8:41

Albert Holguin

5-Dec-11 8:41

Not clear... what do you mean a for loop to reverse the pyramid? ..you mean you want to undo what you just did?

Richard MacCutchan5-Dec-11 8:43

Richard MacCutchan

5-Dec-11 8:43

"Normal" counts from 1 to 5, so I would guess that reverse counts down from 5 to 1.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Yolande MR5-Dec-11 8:47

5-Dec-11 8:47

Richard M.:
reverse count down from 5 to 1 only inverted the pyramid, not REVERSE it !
what I'm trying to create is a RIGHT-ALIGNED pyramid going from 1 to 5 in counts, as oppose to a left-aligned pyramid counting from 1 to 5. Hope you get this.

User 74293385-Dec-11 8:55

5-Dec-11 8:55

With this new information I think I misunderstood what you meant with reversing in my other post; you'll probably want to use this:

for (int i = 1; i < 5; i++){
    for (int j = 1; j < 5-i; j++){
        cout << " ";
    }
    for (; j < 5; j++){
        cout << "*";
    }
    cout << endl;
}

modified 13-Sep-18 21:01pm.

Stefan_Lang5-Dec-11 22:56

Stefan_Lang

5-Dec-11 22:56

You might want to declare j outside the for loop - according to the current C++ standard its scope would end with the end of the for loop and using it after that would result in a compiler error.

User 74293386-Dec-11 5:17

6-Dec-11 5:17

Thanks, good point. I use VC6 most of the time so I didn't get an error.

modified 13-Sep-18 21:01pm.

Stefan_Lang6-Dec-11 5:33

Stefan_Lang

6-Dec-11 5:33

I believe most compilers supported this for a long time. I know for fact that it worked in VC7 (VS 2003), but it does not in VC10 (VS 2010).

Yolande MR5-Dec-11 9:17

5-Dec-11 9:17

Richard M.:
yes, but the asterisk pyramid is on the opposite of that count.

David Crow5-Dec-11 8:44

David Crow

5-Dec-11 8:44

Yolande MR wrote:
I need it has to do something with the spaces, but could not write one. Since i don't have a database to look at.

This is very unclear? Confused | :confused:

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Yolande MR5-Dec-11 8:49

5-Dec-11 8:49

DavidCrow:
What I mean is that I don't know how to write a for loop statement that write out spaces, instead of characters.

David Crow5-Dec-11 9:04

David Crow

5-Dec-11 9:04

A space is just another character. What's wrong with:

for (int x = 0; x < 5; x++)
    cout << " ";
    // printf(" ");
    // printf("%c", ' ');
    // printf("%c", 32);
    // printf("%c", 0x20);

User 74293385-Dec-11 8:45

5-Dec-11 8:45

The idea is to make a pyramid of spaces the same way you made the one you posted, but one character shorter, then write asterisks for the remainder of the line length:

for (int i = 1; i < 5; i++){
    for (int j = 1; j < i; j++){
        cout << " ";
    }
    for (; j < 5; j++){
        cout << "*";
    }
    cout << endl;
}

Also your loops use commas rather than semicolons, which won't compile; I fixed that in my example.

modified 13-Sep-18 21:01pm.

Yolande MR5-Dec-11 9:11

5-Dec-11 9:11

Thaddeus Jones:
THANK YOU. I was able to to twist your codes around to achieve my goal. I know you are testing my c++ skills. Since I just learned how to write an inverted pyramid of asterisk, I was able to substitute asterisks for spaces, and write two pyramids into one project.

User 74293385-Dec-11 9:40

Object instance error? Help

5-Dec-11 9:40

Anytime

modified 13-Sep-18 21:01pm.

ottini935-Dec-11 2:49

ottini93

5-Dec-11 2:49

This is a code to update a process monitoring program when the value changes, the following code is the invoke. To me it looks right, but the code wont function, the error is "Object reference not set to an object instance." What to do?

private void LocalProcesses_Update(int ProcessID, int ValueIndex, string NewValue)
{
if (this.InvokeRequired == true)
{
object[] newList_Item = new object[] { ProcessID, ValueIndex, NewValue };
this.Invoke(new InvokeProcessList(LocalProcesses_Update), newList_Item);
}
else
{
LocalProcesses.BeginUpdate();
LocalProcesses.Items[ProcessID.ToString()].SubItems[ValueIndex.ToString()].Text = NewValue;
LocalProcesses.EndUpdate();
LocalProcesses.Refresh();
}
}

modified 5-Dec-11 9:06am.

Albert Holguin5-Dec-11 3:18

Albert Holguin

5-Dec-11 3:18

What line is the error on? If I had to guess, it's the fact that you have object[] as an object type.

Richard MacCutchan5-Dec-11 3:27

Richard MacCutchan

5-Dec-11 3:27

This looks more like C# code; are you sure you've posted this to the correct forum? It would also help if you put <pre> tags around your code so it is readable.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Albert Holguin5-Dec-11 4:03

Albert Holguin

5-Dec-11 4:03

Good point... that does look like C# now that I look closer.

Richard MacCutchan5-Dec-11 5:31

Richard MacCutchan

5-Dec-11 5:31

I'm also amazed at how many C# programmers apparently have no clue as to the meaning of the message "Object reference not set to an object instance.".

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman