# quantum.gate.CompositeGate class

**Package: **quantum.gate

**Installation Required:** This functionality requires MATLAB Support Package for Quantum Computing.

## Description

A `CompositeGate`

object contains a set of inner gates acting on a small
set of qubits, and a mapping from this small set of qubits to the qubits of the circuit that
contains the composite gate. The `CompositeGate`

object fulfills the purpose
of a subfunction in classical programming, where a set of inner gates can be packaged as a
subcircuit to be used to construct an outer quantum circuit.

You can assign `CompositeGate`

objects to the `Gates`

property of a `quantumCircuit`

object (as a vector of gates).

## Creation

Use the `compositeGate`

creation function to construct a `CompositeGate`

object.

You can also use the `qftGate`

and
`mcxGate`

functions
to construct `CompositeGate`

objects. These functions construct specialized
gates that applies the quantum Fourier transform and multi-controlled X gates,
respectively.

## Properties

## Methods

## Examples

## Version History

**Introduced in R2023a**