What each position in a bitstring means¶
A result such as 01 needs a measurement order before it can be interpreted. Do not reorder qubits by name or assume that the leftmost bit has the largest qubit index.
A digital circuit records logical qubit order at construction. A measurement may select a subset in a different order. Read the saved measurement mapping and bitstring_ordering from the result. Depending on the execution path, the record may expose qubit_order or logical_order; use the fields returned by that run.
For measurement targets (q2, q0), 10 means q2 was measured as 1 and q0 as 0. It tells you nothing about an unmeasured q1. Read multiple measurement registers using their own keys and mappings rather than concatenating strings and guessing the order.
Check with an asymmetric result¶
The Bell-state distribution over 00/11 does not reveal a reversal of the two positions. When checking a conversion or custom mapping, prepare a state that distinguishes them, such as flipping just one qubit. Compare measurement targets, logical order and the returned result.
The bit-order lesson provides an executable asymmetric example. The restricted OpenQASM guide checks both classical-bit mapping and program structure after a round trip.
Graph optimization has a separate node or variable order. 101 selects a and c only if the saved order is (a, b, c). Use the problem’s decoder instead of treating an integer’s binary representation as a node set.
See physical conventions for Analog ground/Rydberg encoding and the result guide for extracting fields.