(C) if

Keyword that checks a condition. If a condition is ?true, then it performs the statement(s) after if, else it performs the statement(s) after else.

include <stdlib.h>

include <stdio.h>


int main()
{
  /* A coin-toss */
  if (rand()%2==0)
  {
    printf("You threw head.");
  }
  else
  {
    printf("You threw tail.");
  }
  return 0;
}

The if-statement can be used for ?debugging by checking certain values. If you do so, check the use of assert, which is an if-statement that can be 'removed' from you code by the ?preprocessor.

Syntax

This program shows the syntaxes of if and if..else. It also puts wise words on the screen

include <iostream>


int main()
{
  //Multiple statements using accolades '{' and '}'
  if (1==2) 
  {
    for (int i=0; i!=10; ++i)
    {
      printf("Life is bad.");
    }
  }
  else 
  {
    for (int i=0; i!=10; ++i)
    {
      printf("Life is good.");
    }
  }
  //You can skip accolades for a single statement
  if (1==2) printf("Life is bad."); //One statement
  else printf("Life is good."); //One statement
  //The else condition is not obligatory
  if (1==2) printf("Life is bad."); //One statement
  printf("Today you should go to the pub."); 
  return 0;
}

if in ?debugging

When you use if's for ?debugging, prefer using assert statements.

Code links

'if' links

last edited (November 24, 2006) by bilderbikkel, Number of views: 829, Current Rev: 1

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