如何根据长度替换单词?

Question

字符串sentence中所有具有给定长度wordLength的单词必须替换为单词myWord。所有参数都来自用户输入，可能会有所不同。我已经尝试过这种方式，但它只返回带有初始单词的初始字符串。

我的源代码:

package main;
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Main {
public static void main(String[] args) throws Exception {
String sentence = "";
int wordLength = 0;
String myWord = "";
InputStreamReader is = new InputStreamReader(System.in);
BufferedReader bis = new BufferedReader(is);
System.out.println("Text input: ");
sentence = bis.readLine();
System.out.println("Word lenth to replace");
wordLength = Integer.parseInt(bis.readLine());
System.out.println("Word to replace to");
myWord = bis.readLine();
Text myText = new Text(myWord, sentence, wordLength);
myText.changeSentence();
System.out.println("New string" + myText.getSentence());
}
}
class Text {
private String mySentence;
private int charNumber;
private String wordToChange;
private String newSentence = "1.";
public Text(String wordToChange, String mySentece, int charNumber) {
this.mySentence = mySentece;
this.wordToChange = wordToChange;
this.charNumber = charNumber;
}
public String getSentence() {
return newSentence;
}
public void changeSentence() {
int firstPos = 0;
int i;
for (i = 0; i < mySentence.length(); i++) {
if (mySentence.charAt(i) == ' ') {
if (i - firstPos == charNumber) {
newSentence = newSentence.concat(wordToChange + " ");
firstPos = i + 1;
} else {
newSentence = newSentence.concat(mySentence.substring(firstPos, i + 1));
firstPos = i + 1;
}
} else if (i == mySentence.length() - 1) {
if (i - firstPos == charNumber) {
newSentence = newSentence.concat(wordToChange + " ");
firstPos = i + 1;
} else {
newSentence = newSentence.concat(mySentence.substring(firstPos, i + 1));
firstPos = i + 1;
}
}
}
}
}

Answer 1

我稍微修改了一下你的代码:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Main {
public static void main(String[] args) {
String sentence = "";
int wordLenght = 0;
String myWord = "";
InputStreamReader is = new InputStreamReader(System.in);
BufferedReader bis = new BufferedReader(is);
try {
System.out.println("Text input: ");
sentence = bis.readLine();
System.out.println("Word lenth to replace");
wordLenght = Integer.parseInt(bis.readLine());
System.out.println("Word to replace to");
myWord = bis.readLine();
} catch (IOException e) {
e.printStackTrace();
}
Text myText = new Text(myWord, sentence, wordLenght);
System.out.println(myText.getChangeSentence());
}
}
class Text {
private String mySentence;
private int charNumber;
private String wordToChange;
private String newSentence = "1.";
public Text(String wordToChange, String mySentece, int charNumber) {
this.mySentence = mySentece;
this.wordToChange = wordToChange;
this.charNumber = charNumber;
}
public String getChangeSentence() {
String[] words = mySentence.split(" ");
for(int i = 0 ; i < words.length ; i++) {
if(words[i].length() == charNumber) {
words[i] = wordToChange;
}
}
for (String word : words) {
newSentence += word + " ";
}
return newSentence;
}
}

输入:这是一个测试字数:2要替换的字:ii

输出:这是一个测试

Answer 2

正如我所看到的，当前认为出现在输入文本中的单词的唯一分隔符是单个空格" "。如果这是真的，那么changeSentence方法可以非常短。不需要逐个字符解析句子。记住空格是一个分隔符，您可以简单地用字符" "分割句子，并将它们收集为单词。之后，您可以遍历单词并替换长度与给定输入字符数匹配的单词。之后，您可以使用前面使用的分隔符将单词连接在一起，就这样了。

示例，如果你想尝试使用循环

public void changeSentence() {
final String[] words = mySentence.split(" ");
for (int i = 0; i < words.length; i++) {
if (words[i].length() == charNumber) {
words[i] = wordToChange;
}
}
newSentence = String.join(" ", words);
}

或使用正则表达式

public void changeSentence() {
String regex = "\b\w{" + charNumber+ "}\b";
newSentence = mySentence.replaceAll(regex, wordToChange);
}

或流API

public void changeSentence() {
newSentence = Arrays.stream(mySentence.split(" "))
.map(s -> s.length() == charNumber ? wordToChange : s)
.collect(Collectors.joining(" "));
}