# How to use QFT operation in Q#?

I see the QFT operation in the document given by Microsoft, but I don't know how to call it.

operation QFT (qs : Microsoft.Quantum.Arithmetic.BigEndian) : Unit is Adj + Ctl


Does this method need to be rewritten? How to set the parameters here? Can I have a brief example?

BigEndian is a data type that is effectively just a wrapper for an array of qubits. If you want to apply QFT to a qubit array register, you need to convert it to BigEndian first:
QFT(BigEndian(register));