While singly-linked lists have many uses, they also present some restrictions. For one thing, singly-linked lists restrict node traversal to a single direction: you can’t traverse a singly-linked list ...

在翻看 Java 1.8 源码发现，LinkedList 里面 checkElementIndex 和 checkPositionIndex 的实现基本一致，那是出于什么目的去实现两个方法呢？