NOTE

Converting Between Lists and Arrays

Safe Java List/array conversion and the mutability semantics of Arrays.asList and modern collection factories.

JavaCreated 01/17/2020Updated 09/15/20261 min readhistorical

This is a historical learning note and may contain outdated or incomplete understanding.

To convert a list to an array, prefer typed APIs such as list.toArray(String[]::new) or list.toArray(new String[0]) depending on the target JDK/style.

Arrays.asList(array) returns a fixed-size list backed by the array: element replacement is reflected, but structural add/remove is unsupported.

If an independent mutable list is needed, wrap it: new ArrayList<>(Arrays.asList(array)). Modern List.of(...) creates an unmodifiable list and rejects null elements.