为什么Java Character.toUpperCase/toLowerCase没有像String.toUpperCase/toLowerCase这样的Locale参数 [英] Why Java Character.toUpperCase/toLowerCase has no Locale parameter like String.toUpperCase/toLowerCase

问题描述

我想知道为什么Character.toUpperCase/toLowerCase没有像String.toUpperCase/toLowerCase这样的Locale参数.

I am wondering that why Character.toUpperCase/toLowerCase has no Locale parameter like String.toUpperCase/toLowerCase.

我必须将任何语言的文本首字母大写.我有2个解决方案:

I have to first uppercase of a text that can be in Any language. I have 2 solutions:

1. 使用Character.toUpperCase

1. Use Character.toUpperCase

String text = "stack overflow";
StringBuilder sb = new StringBuilder(text);   

sb.setCharAt(0, Character.toUpperCase(sb.charAt(0))); // No Locale parameter here.

String out = sb.toString(); //Out: Stack overflow

使用String.toUpperCase

Use String.toUpperCase

Locale myLocale = new Locale(locateId);

String text = "stack overflow";
String text1 = text.substring(0,1).toUpperCase(myLocale );
String text2 = text.substring(1);

String out = text1 + text2; // Out: Stack overflow

对于我的语言环境.两种方法的结果相同.

For my Locale. Both way has the same result.

我的问题是:

• 因为文本可以是任何语言.我应该使用哪种方式?

• Since the text can be in any language. Which way should I use?

为什么Character.toUpperCase/toLowerCase没有Locale参数，因为Character.toUpperCase/toLowerCase和String.toUpperCase/toLowerCase之间没有太大区别，因为字符串是字符数组.

Why Character.toUpperCase/toLowerCase has no Locale parameter because there is not much difference between Character.toUpperCase/toLowerCase and String.toUpperCase/toLowerCase because String is array of Characters.

推荐答案

来自

From the Character#toUpperCase(int) Javadoc,

通常，应使用String.toUpperCase()将字符映射为大写. String案例映射方法比Character案例映射方法具有多个优点. String大小写映射方法可以执行区域设置敏感的映射，上下文敏感的映射和1:M字符映射，而Character大小写映射方法则不能.

In general, String.toUpperCase() should be used to map characters to uppercase. String case mapping methods have several benefits over Character case mapping methods. String case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character case mapping methods cannot.

所以，答案就是您的第二示例(String.toUpperCase)

So, the answer is your second example (String.toUpperCase)

这篇关于为什么Java Character.toUpperCase/toLowerCase没有像String.toUpperCase/toLowerCase这样的Locale参数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！