A register of bits is read as a binary number, **the highest bit first**. With `bit[2] c;`, the outcome `01` means `c[1] = 0` and `c[0] = 1`.

`c = measure q;` measures each qubit of `q` into the bit of `c` with the same index: `q[0]` into `c[0]`, `q[1]` into `c[1]`. You can also measure one qubit at a time:

```qasm
OPENQASM 3.0;
include "stdgates.inc";
qubit[3] q;
bit[3] c;
x q[0];
c[0] = measure q[0];
c[1] = measure q[1];
c[2] = measure q[2];
```

This program flips `q[0]`, so its outcome is `001`. Every result the engine gives, counts and distributions alike, uses this order, and so do the exercises.