How do we use a linked list?

Every linked list operation is built from the same three moves: walk with a pointer, save the arrow you're about to change, and re-point an arrow. This lesson builds the everyday operations from those moves, in four languages.

1. Build a list from an array

Most problems hand you a list, but for testing you'll often want to build one. The trick is a dummy node in front: it gives the loop a place to attach the first real node, so there's no special case for an empty list.