asterisk-loop.c: A basic program about nested loops

As a basic program about nested loops, consider the following code that prints rows with increasing numbers of asteriskes. Commentary after the program explains each element of this program.

#include <stdio.h>

int
main()
{
  int i, j;
  
  printf("Program to print rows with increasing numbers of asterisks.\n");

  for (i = 1; i < 11; i++)
    {
      for (j = 0; j < i; j++)
        {
        printf("*");
        }
      printf("\n");
    }

  return 0;
}

Commentary on the asterisk-loop.c program

• Nested loops are loops that have another loop in the first loop's body. This means that for every iteration of the outer loop, the inner loop is executed as a complete loop.
• When looking at nested loops, it is important that the inner loop must have its variables initialized inside the initialization statement. If this is not the case, then the first iteration of the outer loop leads to the inner loop variable(s) being changed, and upon the second iteration of the outer loop, the inner loop's continue expression depends on the old value of the variable(s) and may not cover the full range of cases desired.
• In the current example, the inner loop is executed a certain number of times based on the outer loop, and a new line for the next row of asterisks is only included in the outer loop body.

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http://www.cs.grinnell.edu/~

created 28 July 2011 by April O'Neill last revised 29 July 2011 by April O'Neill
For more information, please contact Henry M. Walker at walker@cs.grinnell.edu.