strspan(X;Y;C;D)

Returns the position of the first (or last) character in a given string that is found (or not found) in another string.

Syntax

strspan(X;Y;C;D)
bstrspan(X;Y;C;D)

Input

Argument Type Description
X text The string on which to apply the function

A scalar value or the name of a column
Y text Y is the string containing a set of characters to find in X.

A scalar value or the name of a column
C integer Specifies whether the function searches X for characters that are either present or not present in Y

If C=1, the function searches X for characters that are present in Y.

If C=0, the function searches X for characters that are not present in Y.
D integer Specifies in which direction the search is performed

If D=1, the search proceeds in a forward direction (i.e., the first matching character is returned).

If D=-1, the search is reversed (i.e., the last matching character is returned).

Return Value

Returns an integer value corresponding to the first (or last) character in the string X that is found (or not found) in the string Y.

The function searches X for any character that is either present in Y (if C=1) or not present in Y (if C=0).

The search proceeds in a forward direction (i.e., the first matching character in X is returned) if D=1. The search is reversed, returning the last matching character in X, if D=-1.

If X is N/A, then the result is:
  • 0 if D=1
  • N/A if D=-1
If Y is N/A, then the result is:
  • 1 if C=0 and D=1
  • 0 if C=1 and D=1
  • the length of X if C=0 and D=-1
  • N/A if C=1 and D=-1

If C<0, the result is N/A.

Sample Usage

value string2 present direction strspan(value;string2;present;direction)
'apple' 'aeiou' 1 1 1
'apple' 'aeiou' 1 -1 5
'apple' 'aeiou' 0 1 2
'apple' 'aeiou' 0 -1 4
'' 'aeiou' 0 1 0
'apple' '' 0 -1 5

Additional Information

  • strspan is Unicode (UTF-8) compliant and will work with Unicode or plain ASCII text fields. 
  • If passed a string argument that is not legal Unicode, it will by default signal an error (configurable as a user preference). 
  • A corresponding function bstrspan can be used with non-Unicode strings (e.g., binary or legacy encodings).