String.length（）vs Array.length [英] String.length() vs Array.length

问题描述

可能重复：

为什么String.length（）是一个方法？

Java - 数组的长度属性

是否有特定的设计/性能原因为什么String有一个长度方法但Array有一个可变长度？

Was there a specific design/performance reason as to why String has a method for length but Array has a variable length?

推荐答案

没有 Java中的数组类（反射除外）。数组是Java中的一种原语，并且与声明的类有不同的规则。

There is no Array class in Java (other than in reflections). Arrays are "primitives" of a sort in Java and play by different rules from declared classes.

当然是 length（）方法可以在数组上定义，但设计者希望将 length 保留为属性而不是伪方法。 （在某种程度上，这可能使早期Java实现变得更容易。）原因在历史上有些埋没。

Certainly a length() method could have been defined on arrays, but the designers wanted to keep length as a property rather than a pseudo-method. (In part this may have made it easier for early Java implementations.) The reasons are somewhat buried in history.

（一个更好的问题是为什么Java无法决定是否称之为长度，计数或大小这个概念 - 我总是在尝试所有这三个之前尝试所有这三个，然后才能找到合适的聚类。）

(A better question is why Java couldn't decide whether to call the concept "length", "count", or "size" -- I always end up trying all three before I hit on the right one for an aggregating class.)

这篇关于String.length（）vs Array.length的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！