Problem with if statement

This is a discussion on Problem with if statement within the C Programming forums, part of the General Programming Boards category; There is an example in my book that asks to write a program that prints the number 1 to 100 ...

  1. #1
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    Problem with if statement

    There is an example in my book that asks to write a program that prints the number 1 to 100 using 5 columns (Have each number separated from the next by a tab).
    The solution was as following:

    Code:
    #include "stdio.h"
    
    int main()
    {
     int i;
    
     for(i=1; i<=100; i++) {
      printf("%d\t", i);
      if((i%5)==0) printf("\n");
     }
     return 0;
    }
    But I can't understand the if((i%5)==0) printf("\n"); statement. Could anyone explain it for me?
    Last edited by Sharifhs; 08-11-2010 at 10:34 AM.

  2. #2
    a_capitalist_story
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    if i is evenly divisible by 5 then print a newline character.

  3. #3
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    % used in this way, is the modulus (aka "mod") operator. It ignores the normal answer you'd get from a division, and only keeps the remainder.

    So 5 % 5 equals 0, since there is no remainder left over, after you divide 5/5.

    mod operator is used a lot to handle things like columns, on the display. Here, it prints a newline (causing a carriage return and line feed), on the console, every fifth column.

    Tip: 0 / 5 equals 0, so if you want 5 columns in the first row, and you have i starting with zero, (instead of the one in your book), you need to use:
    Code:
    if(column % 5 == 0 && column)
      printf("\n");
    The "&& column" part means that when column is zero, the expression will still evaluate as false, and a newline will not be printed.

  4. #4
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    Quote Originally Posted by rags_to_riches View Post
    if i is evenly divisible by 5 then print a newline character.
    Quote Originally Posted by Adak View Post
    % used in this way, is the modulus (aka "mod") operator. It ignores the normal answer you'd get from a division, and only keeps the remainder.

    So 5 % 5 equals 0, since there is no remainder left over, after you divide 5/5.

    mod operator is used a lot to handle things like columns, on the display. Here, it prints a newline (causing a carriage return and line feed), on the console, every fifth column.

    Tip: 0 / 5 equals 0, so if you want 5 columns in the first row, and you have i starting with zero, (instead of the one in your book), you need to use:
    Code:
    if(column % 5 == 0 && column)
      printf("\n");
    The "&& column" part means that when column is zero, the expression will still evaluate as false, and a newline will not be printed.
    Thanks a million.......things become easier when they are shared

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