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我想从字符串中替换一个单词，就像string.replace("word", "different word");工作方式一样，只是次数有限，假设该单词apple在字符串中被提及 10 次，我希望apples成为5 个，我oranges怎么能做到这一点?

另外，如果可能的话，我希望它是随机的，所以它不会从第一个到第五个apple而是跳过，例如改变1st, 3rd, 4th, 7th, and 8th apple会改变。

谢谢！

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2 回答 2

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我会做随机子字符串并replaceFirst在它们上使用方法。对于子串，使用substring(int beginIndex)和介于 0 和 lengthOfOriginalWord-1-lengthOfWordToReplace 间隔之间的随机开始索引。

    try {

        String originalWord = "alabalaportocalaORANGEalabalaportocalaORANGEalabalaportocalaORANGEalabalaportocalaORANGEalabalaORANGEORANGEaaaaaaa";
        String replacedWord = "ORANGE";
        String replacingWord = "APPLE";
        String substringedWord = "";

        // make sure this is smaller or equal with the number of occurrences, otherwise it's endless loop times
        int numberOfReplaces = 3;
        Random ran = new Random();
        int beginIndex;

        while (numberOfReplaces > 0) {
            // random index between 0 and originalWord.length()-1-replacedWord.length()
            beginIndex = ran.nextInt(originalWord.length()-1-replacedWord.length());
            substringedWord = originalWord.substring(beginIndex);
            if (substringedWord.contains(replacedWord)) {
                originalWord = originalWord.substring(0, beginIndex) + substringedWord.replaceFirst(replacedWord, replacingWord);
                numberOfReplaces--;                 
            }
        }
        System.out.println(originalWord);
    } catch (Exception exc) {
        System.err.println("An error occurred: \n" + exc);
    }

这是运行五次后的输出：

alabalaportocalaORANGEalabalaportocalaORANGEalabalaportocalaORANGEalabalaportocalaAPPLEalabalaAPPLEAPPLEaaaaaaa alabalaportocalaAPPLEalabalaportocalaAPPLEalabalaportocalaAPPLEalabalaportocalaORANGEalabalaORANGEORANGEaaaaaaa alabalaportocalaAPPLEalabalaportocalaORANGEalabalaportocalaORANGEalabalaportocalaAPPLEalabalaAPPLEORANGEaaaaaaa alabalaportocalaORANGEalabalaportocalaORANGEalabalaportocalaORANGEalabalaportocalaAPPLEalabalaAPPLEAPPLEaaaaaaa alabalaportocalaAPPLEalabalaportocalaORANGEalabalaportocalaAPPLEalabalaportocalaAPPLEalabalaORANGEORANGEaaaaaaa

于 2013-04-27T01:42:45.083 回答
1

您可以迭代地使用String#indexOf(String str, int fromIndex)来查找要替换的单词的所有起始索引，然后随机选择其中一些索引（使用例如 shuffledArrayList<Integer>或替代ArrayList<Integer>#remove(Random#nextInt(ArrayList#size))）并使用连接调用构造新字符串String#substring(int beginIndex, int endIndex)

ArrayList<Integer> indices = new ArrayList<>();
int fromIndex = str.indexOf(searchString);
while(fromIndex != -1) {
    indices.add(fromIndex);
    fromIndex = str.indexOf(searchString, fromIndex + 1);
}
于 2013-04-27T01:40:55.813 回答