java - 字符替换(不使用替换)

Question

这段代码是一系列任务，第一个是将句子字符串中的所有“F”替换为“f”，而不使用.replace()方法。我已经完成了，然后我应该将所有的“f”替换为空白，我已经这样做了，但由于某种原因，我所有的大写“F”都变成了一个奇怪的正方形。有任何想法吗？我知道这是基本代码，但只是小步骤。

这是我奇怪的输出:“有一个名叫 []isher 的渔民在一个问题上 isher 或一些 ish；直到一个 ish 笑着把渔夫拉了进来。现在他们正在 ishing 或 []isher ”

谢谢!罗布。

public static void main(String[] args) {
    // orginal string sentence
    String sentence = ("There was a fisherman named Fisher who fished for some fish in a fissure; till a fish with a grin, pulled the fisherman in.  Now they’re fishing the fissure for Fisher. ");
    // data
    char[] originalArray = sentence.toCharArray();
    int i = 0;
    int sLength = sentence.length();
    int positionArray[];
    // combining an int to the array position
    positionArray = new int[sLength];
    /* while loop to check the position of any 'F' or 'f' characters in sentence and identifying it's array position*/
    while (i < sLength) {
        char charAt = sentence.charAt(i);
        if (charAt == 'F') {
            originalArray[i] = 0;
            positionArray[i] = 1;
        }
        i++;

    }
    //redeclaring int i to 0 for the new array
    i = 0;
    //reassigning the character 'F' or 'f' to just 'f to 'sentence'
    sentence = new String(originalArray);
    char[] newArray = sentence.toCharArray();
    while (i < sLength) {
        if (positionArray[i] == 1) {
            newArray[i] = 'f';
        }
        i++;
    //redeclaring int i to 0 for the (part e)
    i = 0;
    //removing every occurance of 'f' (part e)
    while (i < sLength) {
        if (newArray[i] == 'f'  ) {
            newArray[i] = ' ';
        }
        i++;
    //printing to console
    }
    sentence = new String(newArray);
    System.out.println(sentence);
}

}

Answer 1

这是一个使用 Java 8 的解决方案。它利用了 String 的事实。是 CharSequence ，并且您可以获得 IntStream其中的字符或代码点；该解决方案使用 chars :

// Turn all 'F's into 'f's
private int bigFToSmallF(final int inputChar)
{
    return 'F' == inputChar ? 'f' : inputChar;
}

// Turn all 'f's into '0's
private int smallFToZero(final int inputChar)
{
    return 'f' == inputChar ? '0' : inputChar;
}

private String anyFToZeroes(final String input)
{
    final StringBuilder sb = new StringBuilder(input.length());

    input.chars().map(this::bigFToSmallF).map(this::smallFToZero)
        .forEach(sb::appendCodePoint);

    return sb.toString();
}

将此代码插入到 main 中即可完成。