Basic compiling problem for a beginner

Im having problems with this code compiling:

Code:

---

#include <stdio.h>

int main(void)
{
  int i = 0, n = 0, sum = 0;

     
  printf("\n%s", "Enter an integer. \n"); 
  scanf("%d", &i);
           
  for (i > 0)
        {
                n = (2 * i);
          for (i = 1; i <= n; ++i)
                  sum += i;             
        printf("sum = %d\n\n", sum);
  }
       
  /* for (i < 0)
        {
        n = (2 * i)
          for (i = 1; i <= n; ++i)
                  sum += i;             
        printf("sum = %d\n\n", sum););
  }
 */
 
 
  return 0;
}

---

The errors are:
v1.c: In function 'main':
v1.c:15: error: parse error before ')' token
v1.c: At top level:
v1.c:33: error: parse error before 'return'

line 15 is the line with "for (i > 0)". I commented out the second major for loop to simplify troubleshooting.
What boneheaded thing did I do to get these parse errors?
Any help appreciated,
crazychile

Alot is to do with your for loops.

A for loop with no statements can be written as:

Code:

---

for ( ; i < 5;  )

---

if you declared the control variable and the increment/decrement elsewhere in the program.

for (i < 0) is invalid. Perhaps you meant while?

http://www.cprogramming.com/tutorial/c/lesson3.html

Both of your replies were very helpful. I need to write two versions of this. one using only for loops, and the other using only while loops. Your comments help me differentiate the two .

Thank you very much!

You seem to have mixed spaces and tabs in your code. This is not a good thing. As you can see, the indentation is all messed up. Try using one of them only.