/*
The Java Regex or Regular Expression is an API to define a pattern for searching
or manipulating strings.
*/
// Regex Character classes
1. [abc] ----- a, b, or c (simple class)
2. [^abc] -- Any character except a, b, or c (negation)
3. [a-zA-Z] -- a through z or A through Z, inclusive (range)
4. [a-d[m-p]] -- a through d, or m through p: [a-dm-p] (union)
5. [a-z&&[def]] -- d, e, or f (intersection)
6. [a-z&&[^bc]] -- a through z, except for b and c: [ad-z] (subtraction)
7. [a-z&&[^m-p]] -- a through z, and not m through p: [a-lq-z](subtraction)
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