僅反轉句子中的字母而不是 java 中的數字或特殊字符的字符串

Question

我想實現一種方法，在僅反轉句子中的字母[a-zA-Z]后返回字符串，而不是數字或特殊字符。 倒車必須逐字進行。 例如：對於25000rs for 1 LCD它應該是25000sr rof 1 DCL 。

public class Main {
    static String reverseWords(String inputString) { 
    String[] words = inputString.split(" ");

    String reverseString = "";

    for (int i = 0; i < words.length; i++) 
    {
        String word = words[i];

        String reverseWord = "";

        for (int j = word.length()-1; j >= 0; j--) 
        {
            reverseWord = reverseWord + word.charAt(j);
        }

        reverseString = reverseString + reverseWord + " ";
    }
    return reverseString;
}
public static void main(String[] args)
{
    String str1 = "1 cup of hot coffee costs 8.00, whereas cold coffee costs 45.00."; 
    System.out.println(reverseWords(str1));  

    String str2 = "It Costs 25000rs for 1 LCD Projector."; 
    System.out.println(reverseWords(str2)); 

    String str3 = "8990.33"; 
    System.out.println(reverseWords(str3)); 
}
}  

這是我想要的輸出：

1 puc fo toh eeffoc stsoc 8.00，saerehw dloc eeffoc stsoc 45.00。

tI stsoC 25000sr rof 1 DCL rotcejorP。

8990.33

這是我得到的輸出：

1 puc fo toh eeffoc stsoc，00.8 saerehw dloc eeffoc stsoc.00.54

tI stsoC sr00052 rof 1 DCL.rotcejorP

33.0998

Answer 1

您只是在空格字符處進行拆分，這使得每個非空格字符序列都成為一個“單詞”。

此任務是正則表達式Matcher的appendReplacement / appendTail循環的規范用例，當預期的替換邏輯對於 String 上的簡單replaceAll(String regex, String replacement) String過於復雜時，您始終可以使用它：

static final Pattern WORD = Pattern.compile("\\pL+"); // class "L" means "letter"

static String reverseWords(String inputString) { 
    Matcher m = WORD.matcher(inputString);
    if(!m.find()) return inputString;
    StringBuffer sb = new StringBuffer(inputString.length());
    do {
        m.appendReplacement(sb, new StringBuilder(m.group()).reverse().toString());
    } while(m.find());
    return m.appendTail(sb).toString();
}

（從 Java 9 開始，此 API 還支持使用StringBuilder而不是StringBuffer 。

---

但在這種特定情況下，操作也可以稍微更有效地完成：

static String reverseWords(String inputString) { 
    Matcher m = WORD.matcher(inputString);
    if(!m.find()) return inputString;
    StringBuilder sb = new StringBuilder(inputString);
    do {
        for(int ix1 = m.start(), ix2 = m.end() - 1; ix1 < ix2; ix1++, ix2--) {
            sb.setCharAt(ix1, inputString.charAt(ix2));
            sb.setCharAt(ix2, inputString.charAt(ix1));
        }
    } while(m.find());
    return sb.toString();
}

Answer 2

import java.util.*; 

public class Main {
    static String reverse(String inputString) { 
    String[] words = inputString.split(" ");
    boolean set = false; 
    String reverseString = "";

    for (int i = 0; i < words.length; i++) 
    {
        String word = words[i];

        String reverseWord = "";

        for (int j = word.length()-1; j >= 0; j--) 
        {  
            if (Character.isAlphabetic(word.charAt(j))){
                
            reverseWord = reverseWord + word.charAt(j);
            set = false; 
        }else{
            set = true ; 
            break ; 
        }
        }
        if(set == true){
            reverseString = reverseString + reverseWord + word +  " "; 
        }
        
        reverseString = reverseString + reverseWord +  " ";
      
    }
    return reverseString;
}

public static void main(String[] args)
{
    String st1 = "1 cup of hot coffee costs 8.00, whereas cold coffee costs 45.00.";
    System.out.println(Main.reverse(st1));  

    String st2 = "It Costs 25000rs for 1 LCD Projector."; 
    System.out.println(Main.reverse(st2)); 

    String st3 = "8990.33"; 
    System.out.println(Main.reverse(st3)); 
    
    String st4 = "Hello Everyone Today we are going to learn 1-10 table."; 
    System.out.println(Main.reverse(st4)); 
}
}