Position

version 11 (Modified)

Position (find; aString{; start{; lengthFound{; *}}}) Number

Position returns the position of the first occurrence of find in aString.

If aString does not contain find, it returns a zero (0).

If Position locates an occurrence of find, it returns the position of the first character of the occurrence in aString.

If you ask for the position of an empty string within an empty string, Position returns zero (0).

By default, the search begins at the first character of aString. The optional start parameter can be used to specify the character where the search will begin in aString.

The lengthFound parameter, if passed, returns the length of the string actually found by the search. This parameter is necessary to be able to correctly manage letters that can be written using one or more characters (e.g.: æ and ae, ß and ss, etc.).

Note that when the * parameter is passed (see below), these letters are not considered as equivalent (æ # ae); in this mode, lengthFound is always equal to the length of find (if an occurrence is found).

By default, the command makes global comparisons that take linguistic particularities and letters that may be written with one or more characters (for example æ = ae) into account. On the other hand, it is not diacritical (a=A, a=à and so on) and does not take "ignorable" characters such as carriage returns into account (Unicode specification).

To modify this functioning, pass the asterisk * as the last parameter. In this case, comparisons will be based on character codes. You must pass the * parameter:

• If you want to take special characters into account, used for example as delimiters (carriage returns, Char(1), etc.),

• If the evaluation of characters must be case sensitive and take accented characters into account (a#A, a#à and so on).

Note that in this mode, the evaluation does not handle variations in the way words are written.

Warning: You cannot use the @ wildcard character with Position. For example, if you pass "abc@" in find, the command will actually look for "abc@" and not for "abc" plus any character.

1. This example illustrates the use of Position. The results, described in the comments, are assigned to the variable vlResult.

   vlResult := Position ("ll"; "Willow")  ` vlResult gets 3 
   vlResult := Position (vtText1; vtText2)  ` Returns first occurrence of vtText1 in vtText2
   vlResult := Position ("day"; "Today is the first day";1) ` vlResult gets 3
   vlResult := Position ("day"; "Today is the first day";4) ` vlResult gets 20
   vlResult := Position ("DAY"; "Today is the first day";1;*) ` vlResult gets 0

   vlResult := Position ("œ"; "Bœuf";1;$length) ` vlResult =2, $length = 1

2. In the following example, the lengthFound parameter can be used to search for all the occurrences of "aegis" in a text, regardless of how it is written:

   $start:=1 
   Repeat
      vlResult := Position ("aegis";$text;$start;$lengthfound)
      $start:= $start+$lengthfound
   Until(vlResult =0)

Comparison Operators, Substring.