field

The field called name, or null if the object does not have one.

A binary search over the field ids, comparing the target's UTF-8 bytes against the dictionary in place — no String is built and no value byte is touched, so a lookup costs log2(fieldCount) byte comparisons regardless of how large the values are.

This relies on the specification's guarantee that field ids appear in lexicographic order of their names. A file that violates it may report a present field as absent; it will not produce a wrong value.

Throws