charAt

A CharSequence provides only a single method for accessing its characters : charAt ( x ) .

CharSequence只提供了一个方法来访问它的字符：charAt（x）。

Although the charAt implementation directly returns char primitives , the iterator implementation must box each char into a Character object .

而charAt实现直接返回char原语，迭代器实现必须将每个char装箱为一个Character对象。

The reason is that Rope represents lazy substrings using a dedicated class , allowing the implementation of charAt to remain simple for regular ropes .

原因是Rope使用专门的类来表示延迟子串（lazysubstring），因此使普通rope的charAt的实现保持简单。

Astute readers might wonder why charAt is more than seven times faster than the iterator , given that both provide O ( 1 ) access time .

聪明的读者可能想知道既然大家都提供0（1）的访问时间，为什么charAt会比迭代器快7倍。

If the iterator can 't move backward the required distance , then the default charAt routine is executed to obtain the character value & a scenario that one hopes will occur rarely .

如果迭代器不能后移指定的距离，那么就执行默认的charAt例程取得字符的值&这种情况很少发生。