---
title: IntegerComparator (v2.1)
description: API reference for qiskit.circuit.library.IntegerComparator in qiskit v2.1
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/2.1/qiskit.circuit.library.IntegerComparator
---

# IntegerComparator

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

[GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.1/qiskit/circuit/library/arithmetic/integer_comparator.py#L27-L169)

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`):

$$
|i\rangle_n |0\rangle \mapsto |i\rangle_n |i \geq L\rangle
$$

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*](https://docs.python.org/3/library/functions.html#int) *| None*) – Number of state qubits. If this is set it will determine the number of qubits required for the circuit.
- **value** ([*int*](https://docs.python.org/3/library/functions.html#int) *| None*) – The fixed value to compare with.
- **geq** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – If True, evaluate a `>=` condition, else `<`.
- **name** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)) – Name of the circuit.

## Attributes

### geq

Return whether the comparator compares greater or less equal.

**Returns**

True, if the comparator compares `>=`, False if `<`.

### num\_state\_qubits

The number of qubits encoding the state for the comparison.

**Returns**

The number of state qubits.

### 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.

**Example**

```python
from qiskit import QuantumCircuit

qc = QuantumCircuit(2, 2, name="my_circuit")
print(qc.name)
```

```text
my_circuit
```