Boolean for whether a string contains a substring

Question

Suppose I have a text variable $$string. How can I write a boolean to check whether $$string contains the text $$substring?

e.g. if $$string is "foobar" and $$substring is "oo", then the result should be True, and if the $$string is "foo" and $$substring is "bar" the result should be False.

Answer 1

For a problem like this I'm partial to the PatternCount function:

 PatternCount($$string ; $$substring)

You should then get back false = 0 or true >= 1. You can force true to 1 as follows:

 PatternCount($$string ; $$substring) > 0

Function Definition here: http://fmhelp.filemaker.com/fmphelp_10/en/html/func_ref3.33.73.html

Answer 2

Use the Position function:

Position($$string;$$substring;1;1)>0

Note: Position($$string;$$substring;a;b) checks whether $$substring is contained at least b-times in $$string from starting position a, and returns where the b th occurrence is located in $$string, or -1 if there is no b th occurrence. Counting starts from 1.