# IntegerComparator

*class *`qiskit.circuit.library.IntegerComparator(num_state_qubits=None, value=None, geq=True, name='cmp')`

Bases: `BlueprintCircuit`

Integer Comparator.

Operator compares basis states $|i\rangle_n$ against a classically given integer $L$ of fixed value and flips a target qubit if $i \geq L$ (or $<$ depending on the parameter `geq`

):

This operation is based on two’s complement implementation of binary subtraction but only uses carry bits and no actual result bits. If the most significant carry bit (the results bit) is 1, the $\geq$ condition is `True`

otherwise it is `False`

.

Create a new fixed value comparator circuit.

**Parameters**

**num_state_qubits**(*int*(opens in a new tab)*| None*) – Number of state qubits. If this is set it will determine the number of qubits required for the circuit.**value**(*int*(opens in a new tab)*| None*) – The fixed value to compare with.**geq**(*bool*(opens in a new tab)) – If True, evaluate a`>=`

condition, else`<`

.**name**(*str*(opens in a new tab)) – Name of the circuit.

## Attributes

### ancillas

A list of `AncillaQubit`

s in the order that they were added. You should not mutate this.

### calibrations

Return calibration dictionary.

The custom pulse definition of a given gate is of the form `{'gate_name': {(qubits, params): schedule}}`

### clbits

A list of `Clbit`

s in the order that they were added. You should not mutate this.

### data

### geq

Return whether the comparator compares greater or less equal.

**Returns**

True, if the comparator compares `>=`

, False if `<`

.

### global_phase

The global phase of the current circuit scope in radians.

### instances

Default value: `178`

### layout

Return any associated layout information about the circuit

This attribute contains an optional `TranspileLayout`

object. This is typically set on the output from `transpile()`

or `PassManager.run()`

to retain information about the permutations caused on the input circuit by transpilation.

There are two types of permutations caused by the `transpile()`

function, an initial layout which permutes the qubits based on the selected physical qubits on the `Target`

, and a final layout which is an output permutation caused by `SwapGate`

s inserted during routing.

### metadata

Arbitrary user-defined metadata for the circuit.

Qiskit will not examine the content of this mapping, but it will pass it through the transpiler and reattach it to the output, so you can track your own metadata.

### num_ancillas

Return the number of ancilla qubits.

### num_captured_vars

The number of real-time classical variables in the circuit marked as captured from an enclosing scope.

This is the length of the `iter_captured_vars()`

iterable. If this is non-zero, `num_input_vars`

must be zero.

### num_clbits

Return number of classical bits.

### num_declared_vars

The number of real-time classical variables in the circuit that are declared by this circuit scope, excluding inputs or captures.

This is the length of the `iter_declared_vars()`

iterable.

### num_input_vars

The number of real-time classical variables in the circuit marked as circuit inputs.

This is the length of the `iter_input_vars()`

iterable. If this is non-zero, `num_captured_vars`

must be zero.

### num_parameters

### num_qubits

Return number of qubits.

### num_state_qubits

The number of qubits encoding the state for the comparison.

**Returns**

The number of state qubits.

### num_vars

The number of real-time classical variables in the circuit.

This is the length of the `iter_vars()`

iterable.

### op_start_times

Return a list of operation start times.

This attribute is enabled once one of scheduling analysis passes runs on the quantum circuit.

**Returns**

List of integers representing instruction start times. The index corresponds to the index of instruction in `QuantumCircuit.data`

.

**Raises**

**AttributeError**(opens in a new tab) – When circuit is not scheduled.

### parameters

### prefix

Default value: `'circuit'`

### qregs

Type: `list[QuantumRegister]`

A list of the `QuantumRegister`

s in this circuit. You should not mutate this.

### qubits

A list of `Qubit`

s in the order that they were added. You should not mutate this.

### value

The value to compare the qubit register to.

**Returns**

The value against which the value of the qubit register is compared.

### name

Type: `str`

A human-readable name for the circuit.

### cregs

Type: `list[ClassicalRegister]`

A list of the `ClassicalRegister`

s in this circuit. You should not mutate this.

### duration

Type: `int | float | None`

The total duration of the circuit, set by a scheduling transpiler pass. Its unit is specified by `unit`

.

### unit

The unit that `duration`

is specified in.