如何用兩個單引號替換單引號的奇數

Question

我想在Java中的字符串中添加轉義字符"'" （單引號），但僅當使用正則表達式出現的次數奇數時

例如：

1. 如果字符串類似於"string's property"則輸出應為"string''s property"
2. 如果字符串類似於"string''s property"則輸出應為"string''s property"

Answer 1

嘗試這個 ：

\'(\')?

演示（用'代替）

http://regexr.com?38eeh

Answer 2

試試這個代碼（偶數）。

public static void main(String[] args) {
    String str = "a''''''b";
    str = str.replaceAll("[^']'('')*[^']", "###");
    System.out.println(str);
}

然后嘗試這個（奇數）。

public static void main(String[] args) {
    String str = "a'''''''b";
    str = str.replaceAll("[^']'('')*[^']", "###");
    System.out.println(str);
}

Answer 3

嘗試這個：

// input that will be replaced
String replace = "string's property";
// input that won't be replaced
String noReplace = "string''s property";
// String representation of the Pattern for both inputs
//                 |no single quote before...
//                 |    |single quote 
//                 |    | |... no single quote after
String pattern = "(?<!')'(?!')";
// Will replace found text with main group twice --> found
System.out.println(replace.replaceAll(pattern, "$0$0"));
// Will replace found text with main group twice --> not found, no replacement
System.out.println(noReplace.replaceAll(pattern, "$0$0"));

輸出：

string''s property
string''s property