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itemtoindex

# $EPIC: itemtoindex.txt,v 1.2 2006/08/01 03:40:36 sthalik Exp $

Synopsis:

$indextoitem(<array> <index number>)
$itemtoindex(<array> <item number>)

Technical:

These functions are used to convert between array item numbers are index numbers.

Item numbers are counted incrementally as items are added to an array, starting at 0 (zero). Each new item uses the next available item number; if there are 5 items in an array, the next item that may be added is item number 5 (remember that we count from zero… 5 items is 0..4).

Index numbers represent each items position in the array when sorted. Items are sorted based on their ascii values. This is generally alphabetical; however, since it is based on ascii values, all capital letters are sorted after all lowercase letters. It follows a sorting algorithm similar to the $sort() function's.

Practical:

The $indextoitem() function converts an index number in the given array to its corresponding item number; $itemtoindex() does just the opposite. This is mostly useful in conjunction with $igetitem() or $ifinditem(), allowing an array to be dealt with in a logical order.

Returns:

  -2   cannot find index/item number in array
  -1   cannot find named array
> -1   item number corresponding to given index number (and vice verse)

Examples:

$setitem(booya 0 hello)
$setitem(booya 1 goodbye)
$itemtoindex(booya 0)                 returns 1
$indextoitem(booya 1)                 returns 0
$itemtoindex(foobar 0)                returns -1
$itemtoindex(booya 100)               returns -2
itemtoindex.txt · Last modified: 2006/08/01 03:45 (external edit)