替换字符串中的出现

Question

如何替换给定String的出现，但没有第一次出现和最后一次出现？输入来自键盘。示例：

INPUT: "a creature is a small part of a big world"
        a
        the
OUTPUT: "a creature is the small part of a big world"

另一个例子：

INPUT: "a creature is a small part"
       a
       the
OUTPUT: "a creature is a small part"

在最后一个字符串中，字符串保持不变，因为这两个事件（即字符'a'）都是第一个和最后一个出现。

Answer 1

您可以使用String.replaceFirst(String, String)：

String a = "a creature is a small part of a big world";
String b = "a";
String c = "the";
String d = a.replaceFirst(" " + b + " ", " " + c + " ");
System.out.println(d);

...打印出：

a creature is the small part of a big world

阅读文档以获取更多信息：String documentation

---

编辑：

对不起，我误解了你的问题。这是替换第一个和最后一个除外的所有出现的示例：

String a = "a creature is a small part of a big world";
String b = "a";
String c = "the";

String[] array = a.split(" ");
ArrayList<Integer> occurrences = new ArrayList<>();

for (int i = 0; i < array.length; i++) {
    if (array[i].equals(b)) {
        occurrences.add(i);
    }
}

if (occurrences.size() > 0) {
    occurrences.remove(0);
}
if (occurrences.size() > 0) {
    occurrences.remove(occurrences.size() - 1);
}
for (int occurrence : occurrences) {
    array[occurrence] = c;
}

a = String.join(" ", array);
System.out.println(a);

---

编辑：

为事件集合使用其他类型：

String a = "a creature is a small part of a big world";
String b = "a";
String c = "the";

String[] array = a.split(" ");
Deque<Integer> occurrences = new ArrayDeque<>();

for (int i = 0; i < array.length; i++) {
    if (array[i].equals(b)) {
        occurrences.add(i);
    }
}

occurrences.pollFirst();
occurrences.pollLast();

for (int occurrence : occurrences) {
    array[occurrence] = c;
}

String d = String.join(" ", array);
System.out.println(d);

Answer 2

package com.example.functional;

import java.util.Arrays;
import java.util.List;
import java.util.function.UnaryOperator;

public class StringReplacementDemo {

    public static void appendString(String str){
        System.out.print(" "+str);
    }
    /**
     * @param str1
     * @param output2 
     * @param input 
     */
    public static void replaceStringExceptFistAndLastOccerance(String str1, String input, String output2) {
        List<String> list = Arrays.asList(str1.split(" "));
        int index = list.indexOf(input);
        int last = list.lastIndexOf(input);
        UnaryOperator<String> operator = t -> {
            if (t.equals(input)) {
                return output2;
            }
            return t;
        };
        list.replaceAll(operator);
        list.set(index, input);
        list.set(last, input);

        list.forEach(MainClass::appendString);
    }

    public static void main(String[] args) {

        String str1 = "a creature is a small part";
        String input = "a";
        String output ="the";
        replaceStringExceptFistAndLastOccerance(str1,input,output);
    }
}