Method startsWith

javascript/0208-implement-trie-prefix-tree.js:48–58

(prefix, node = this.root)

    /* Time O(N) | Space O(1) */
    startsWith(prefix, node = this.root) {
        for (const char of prefix) {
            const child = node.children[char] || null;

            if (!child) return false;

            node = child;
        }

        return true;
    }
}