basic.index Function/BASIC Program


Command basic.index Function/BASIC Program
Applicable release versions: AP, R83
Category BASIC Program (486)
Description searches through a given "string.expression" for the occurrence of the character or substring specified by "substring.expression" and if found, returns the numeric position at which the nth occurence of the substring begins. Null strings are skipped.

The "num.expression" defines a particular occurrence to find, (nth occurrence).

If the nth occurence of the specified substring is not found, "0" (zero) is returned.
Syntax index(string.expression, substring.expression, num.expression)
d.position = index("abcdefg","d",1)

This returns the value, "4", to the variable "test", since 
the first occurrence of "d" is found in the fourth position of the 

on index("abcdefg",response,1) goto 10,20,30,40,50,60,70

This example exploits the fact that "index" returns a number 
indicating the position of the search character. For instance, if 
"response" is the letter "d", then it will goto statement 
label 40.

 input ans,1
 until ans#'' and index('abc',ans,1) do repeat

If "ans" is not null and is either an a, b, c, ab, or bc, the loop is 
terminated.  Notice that the null condition must be tested separately since a 
null value for "ans" results in a "1" from the 
"index" function.
Related basic.statements