LiveCode Forums.

This stack contains 3 fields: fORIGIN, fLIST and fOUTPUT

fLIST contains the list of permitted characters (in this case the consonants of the English alphabet).

The button will "bite" the first character from the string in fld fORIGIN and if it matches one of the letters in fld fLIST put it into fld 'fOUTPUT

This is horribly primitive and needs a REPEAT loop, but it proves its point.

Here's a cleaned-up version, with a repeat loop.

There is an option to perform using fields

and

an option to use strings (which should, with great long strings be quicker).