if(true)
  puts("true");
else
  puts("false")

if(true) {
  if(false) {
    if(true) {      
      if(false)
        puts("you can do many things with loops");
      puts("just be careful with the start and the end braces");
    } else
      puts("3f");
  } else {
    puts("by the way there are tons of code from the web just try googling :-)");  
    puts("by the way puts acts like printf :-)");
    puts("a nested loop can be confusing so try to avoid a deep one.");
  }
}

if() {
  //if expression evaluate to true
  //then do the codes here, ex.
  printf("True");
} else {
  //if expression evaluated to false 
  //then do codes here, ex.
  printf("False");
}

My previous example is just an extension of this simple code fragment all i did
was insert some if/else inside another if/else ok :-).

//are comments

int main() {
  printf("%d", factorial(5)); 
  //will do something like 5 x 4 x 3 x 2... no need for x 1 since the answer is the same
  return 0;
}

int factorial(n) {
  if(n > 1)
    return (n * factorial(n - 1));
}

Attention...

New program to be share

//this code is called recursion, a function that called itself
int fact(int n) {
  if(n < 1)
    return 1;
  else
    return (n * fact(n - 1));		
}

//inside your main function you can call it like:
int main() {
  printf("%d", fact(5));
  //and it will print 120 try it :-)
}