Modify Variable Action is a useful action that can alter rule variable values. Actions that works after this action uses altered values.

On last two cases we used Regular Expressions.

• When Regex used as Find value it replaces variable with replace value if Find value successfully matches.
• When Regex used as Replace value it replaces variable with first regex group (the part in paranthesis) if regex matches.

Suppose you are using NumberPad Value Entered rule to scan customer cards through magnetic card reader. Some card scanners sends mag card data between ; and ? characters. As you know we can read entered number with NumberpadValue parameter so before using NumberpadValue parameter you might want to trim these characters.

[;|%](.*)\? regular expression trims starting ; or % char and ending ? character. If we call this action before using NumberpadValue in Numberpad Value Entered rule we'll read trimmed value.