--- title: IntegerComparator (v1.1) description: API reference for qiskit.circuit.library.IntegerComparator in qiskit v1.1 source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/1.1/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/1.1/qiskit/circuit/library/arithmetic/integer_comparator.py#L25-L243) 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 ### 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`](/docs/api/qiskit/1.1/qiskit.transpiler.TranspileLayout "qiskit.transpiler.TranspileLayout") object. This is typically set on the output from [`transpile()`](/docs/api/qiskit/1.1/compiler#qiskit.compiler.transpile "qiskit.compiler.transpile") or [`PassManager.run()`](/docs/api/qiskit/1.1/qiskit.transpiler.PassManager#run "qiskit.transpiler.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()`](/docs/api/qiskit/1.1/compiler#qiskit.compiler.transpile "qiskit.compiler.transpile") function, an initial layout which permutes the qubits based on the selected physical qubits on the [`Target`](/docs/api/qiskit/1.1/qiskit.transpiler.Target "qiskit.transpiler.Target"), and a final layout which is an output permutation caused by [`SwapGate`](/docs/api/qiskit/1.1/qiskit.circuit.library.SwapGate "qiskit.circuit.library.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`](#qiskit.circuit.library.IntegerComparator.num_input_vars "qiskit.circuit.library.IntegerComparator.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`](#qiskit.circuit.library.IntegerComparator.num_captured_vars "qiskit.circuit.library.IntegerComparator.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**](https://docs.python.org/3/library/exceptions.html#AttributeError) – 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`](#qiskit.circuit.library.IntegerComparator.unit "qiskit.circuit.library.IntegerComparator.unit"). ### unit The unit that [`duration`](#qiskit.circuit.library.IntegerComparator.duration "qiskit.circuit.library.IntegerComparator.duration") is specified in.