Java字符开关

Question

在Java中切换字符的简单方法是什么？说我有以下内容:

String testString = "Hello World.";

// I know this doesn't work
testString = testString.replace('o', 'e');

我想用'o'切换'e',我知道这不会有用......请让我知道我需要做什么

Answer 1

 String testString = "Hello World.";
 String replacedString = testString.replaceAll("o", "~")
                                   .replaceAll("e","o")
                                   .replaceAll("~","e");

好吧,只要你的字符串没有〜