[RegExp] GST Number Validation

gst.js

/^
 (0[0-9]|1[1-9]|2[0-9]|3[0-7]) // matches the first two digits. This needs to be within the 01-37 range
 [A-Z]{3}                      // first three letters of the PAN Card
 [CPHFATBLJG]{1}               // PAN limited set control character
 [A-Z]{1}                      // PAN non-limited set control character
 \d{4}                         // PAN Identity numbers 
 [A-Z]{1}                      // PAN non-limited set control character
 \d{1}                         // GST control number
 [A-Z0-9]{2}                   // GST non-limited control characters
$/g
 
// one-liner
/(0[0-9]|1[1-9]|2[0-9]|3[0-7])[A-Z]{3}[CPHFATBLJG]{1}[A-Z]{1}\d{4}[A-Z]{1}\d{1}[A-Z0-9]{2}/g