java - 想要在 Java 中专门进行字符串拆分

Question

我想对下面的字符串进行字符串拆分

String ToSplit = "(2*(sqrt 9))/5";

进入以下字符串数组:

String[] Splitted = {"(", "2", "*", "(", "sqrt", "9", ")", ")", "/", "5"};

如您所见，字符串 ToS​​plit 没有空格，我很难将单词“sqrt”从其余元素中拆分出来，因为它是一个完整的单词。我正在做:

String[] Splitted = ToSplit.split("");

单词“sqrt”被拆分为{“s”、“q”、“r”、“t”}(很明显)，我希望将其拆分为整个单词，以便将字符串拆分为如上所示

如何将单词“sqrt”(作为 1 个元素)与其他单词分开？

提前致谢。

Answer 1

这是一个工作解决方案，它根据环顾四周进行拆分。请参阅下面的代码以获取解释。

String input = "(2*(sqrt 9))/5";
String[] parts = input.split("(?<=[^\\w\\s])(?=\\w)|(?<=\\w)(?=[^\\w\\s])|(?<=[^\\w\\s])(?=[^\\w\\s])|\\s+");
for (String part : parts) {
    System.out.println(part);
}

(
2
*
(
sqrt
9
)
)
/
5

正则表达式交替中有四个术语，这是每个术语的作用:

(?<=[^\\w\\s])(?=\\w)
split if what precedes is neither a word character nor whitespace, AND
what follows is a word character
e.g. split (2 into ( and 2

(?<=\\w)(?=[^\\w\\s])
 split if what precedes is a word character AND
 what follows is neither a word character nor whitespace
e.g. split 9) into 9 and )

(?<=[^\\w\\s])(?=[^\\w\\s])
split between two non word/whitespace characters
e.g. split )/ into ) and /

\\s+
finally, also split and consume any amount of whitespace
as a separator between terms
e.g. sqrt 9 becomes sqrt and 9