Having some newb troubles

Hi,
I'm trying to write a console app that will take in a base 10 number and output that number in binary form. I created a character array for the binary number and a couple of for loops (one to mod the number and divide. One to print the contents of the array.) but, I must have the syntax of something incorrect. I have looked at the code for a couple hours though and cannot figure out the issue. It seems to me when I run the app like the for loops are not even running. Anyways tia for any help.

Code:

---

#include <iostream>
#include <stdlib.h>

using namespace std;

int main(void) {
  int num = 0;
  int i = 0;
  //array to store the binary digits.  all values are initialized to 0.
  int binary[8] = {0};
 
  cout << "Please enter a base10 number between 0 and 255:" << endl;
  cin >> num;
 
  //loop from 7 to 0 modding the number by 2 and then dividing it in half.
  for (i = 7; i < 0; i--) {
    binary[i] = (num % 2);
    num = num / 2;
  }

  cout << "Your number is:" << endl;
 
  //loop through the binary array printing each digit.
  for (i = 0; i > 7; i++) {
    cout << binary[i];
  }
 
  cout << endl;
         
  return 0;
}

---

Hi in your first for loop you have this

for (int i = 7; i < 0; i--)

and it should be this
for (int i = 7; i > -1; i--)

in the second for loop you have this

for (int i = 0; i > 7; i++)

and it should be this
for (int i = 0; i < 8; i++)

Regards William

Thanks for the fast response. I knew I was staring too hard and overlooking something silly :D. Thanks again.

err why would the second loop be

Code:

---

for (int i = 0; i < 8; i++)

---

when the valid array elements are 0 - 7?

Nm. Another retarded question lol. For some reason I had confused the middle argument of the for loop as the "while this condition is false" when in reality it's saying "while this condition is true". I think anyways. Thanks again for the help.

it depends what kind of stuff you have in your array .....
take an string array for eksample......

MAX specifies the max. length of the string (6 characters for "Monday" plus the terminating null ('\0') makes 7

You see if you are displaying 7 digits, the loop should be from 0 to 7.....

take a look at this code

Code:

---

string_array.cpp

---

int main()
{
const int MAX = 7;

char MyArray[MAX] = {"Monday"};

//runing this loop for 7 times

for( int i=0; i<MAX; i++ )
cout << MyArray[i] << endl;

return 0;
}

Yeah I see what your saying. I had both uses in my app and had both set backwards heh.

Quote:

---

Originally posted by agony


You see if you are displaying 7 digits, the loop should be from 0 to 7.....

---

This sounds confusing; you want to do the loop 7 times, with values from 0-6. Your code itself is correct, because (i = 0; i < 7; i++) runs the loop with i = 0,1,2,3,4,5,6 (as it should).

Well it was almost correct.

Code:

---

#include <iostream>
#include <stdlib.h>

using namespace std;

int main(void) {
  int num = 0, num1 = 0;
  int i = 0;
  //array to store the binary digits.  all values are initialized to 0.
  int binary[8] = {0};
  cout << "Please enter a base10 number between 0 and 255:" << endl;
  cin >> num;
 
  num1 = num;
 
  //loop from 7 to 0 modding the number by 2 and then dividing it in half.
  for (i = 7; i >= 0; i--) {
      binary[i] = (num % 2);
      num = num / 2;
  }

  cout << num1 << " in binary is: ";
 
  //loop through the binary array printing each digit.
  for (i = 0; i <= 7; i++) {
    cout << binary[i];
  }
 
  cout << endl;
 
  return 0;
}

---

That is the correct code. Both loops had the condition of the for loop backwards. Also they had to be changed to >= and <= so the last element of the array was included. Why I could'nt figure that out I dunno, seemed like the harder I tried the further I was from getting anywhere heh. I knew the loops were'nt running but I just did'nt put 2 and 2 together. Instead I tried the "stare really hard till you find something" method. :rolleyes: