Welcome to the Lounge

(JS)
var arr =[0,1,2,3,4,5];
var valueToFind = 3;

for(i=0;i<arr.length;i++) 
{
      if(arr[i]==valueToFind)
      {
	break;
      } 
}

console.log(i);
Then go on to calculate an offset or something from this index.

honey the codewitch wrote:

} // braces copyright Sander Rossel

public int IndexOf(T item) 
{
   var ic = Count;
   var i = 0;
   for(;i<ic;++i) 
   {
      if(Equals(item,this[i]))
         return i; // return instead of break but same basic concept
   }
   return -1;
}

for(int i = 0;i<arr.Length && arr[i]!=valueToFind;i++) 
{
}

int i = 0;
while (i<arr.Length && arr[i]!=valueToFind)
i++;

Book[] arr = books; 
for(int i = 0; i<arr.Length; i++) 
{
  int books_index = i;
  Book book = arr[books_index];

  if(book.name == find_book) {
    return books_index;
  }
  else if(book.name != find_book) {
    continue;
  }
  else {
    found_flag = false;
  }
}