Java中是否内置了一个函数,使字符串中每个单词的第一个字符大写,而不影响其他字符?

例子:

乔恩·斯基特->乔恩·斯基特 miles o'Brien -> miles o'Brien (B仍然是大写,这排除了Title Case) 老麦当劳->

*(老麦当劳也会被发现,但我不指望它有那么聪明。)

快速浏览一下Java字符串文档就会发现只有toUpperCase()和toLowerCase(),它们当然没有提供所需的行为。当然,谷歌的结果主要是这两个函数。它看起来像一个已经被发明出来的轮子,所以问一下也无妨,这样我以后就可以用它了。


当前回答

public static String toTitleCase(String word){
    return Character.toUpperCase(word.charAt(0)) + word.substring(1);
}

public static void main(String[] args){
    String phrase = "this is to be title cased";
    String[] splitPhrase = phrase.split(" ");
    String result = "";

    for(String word: splitPhrase){
        result += toTitleCase(word) + " ";
    }
    System.out.println(result.trim());
}

其他回答

如果你更喜欢番石榴……

String myString = ...;

String capWords = Joiner.on(' ').join(Iterables.transform(Splitter.on(' ').omitEmptyStrings().split(myString), new Function<String, String>() {
    public String apply(String input) {
        return Character.toUpperCase(input.charAt(0)) + input.substring(1);
    }
}));

最基本和最简单的理解方法(我认为):

import java.util.Scanner;

public class ToUpperCase {
    static Scanner kb = new Scanner(System.in);

    public static String capitalize(String str){
        /* Changes 1st letter of every word 
           in a string to upper case
         */
        String[] ss = str.split(" ");
        StringBuilder[] sb = new StringBuilder[ss.length];
        StringBuilder capped = new StringBuilder("");
        str = "";

        // Capitalise letters
        for (int i = 0; i < ss.length; i++){
            sb[i] = new StringBuilder(ss[i]); // Construct and assign
            str += Character.toUpperCase(ss[i].charAt(0)); // Only caps
            //======================================================//

            // Replace 1st letters with cap letters
            sb[i].setCharAt(0, str.charAt(i)); 
            capped.append(sb[i].toString() + " ");  // Formatting
        }
        return capped.toString();
    }

    public static void main(String[] args){
        System.out.println(capitalize(kb.nextLine()));
    }
}

您也可以非常简单地这样做,并保留任何双空格、前导空格和尾随空格

public static String capitalizeWords(String text) {

    StringBuilder sb = new StringBuilder();
    if(text.length()>0){
        sb.append(Character.toUpperCase(text.charAt(0)));
    }
    for (int i=1; i<text.length(); i++){
        String chPrev = String.valueOf(text.charAt(i-1));
        String ch = String.valueOf(text.charAt(i));

        if(Objects.equals(chPrev, " ")){
            sb.append(ch.toUpperCase());
        }else {
            sb.append(ch);
        }

    }

    return sb.toString();

}

我做了这个小类,可以用来大写一个句子中的每个单词。如果不是空格,可以更改字符串中的单词分隔符。

package com.ecnews.ecnews_v01.Helpers;

  public class Capitalize {

  String sentence;
  String separator = " ";

  public Capitalize(String sentence) {
    this.sentence = sentence;
  }

  public void setSeparator(String separator) {
    this.separator = separator;
  }

  public String getCapitalized() {
    StringBuilder capitalized = new StringBuilder("");
    for (String word : sentence.split(separator)) {
        capitalized.append(separator+Character.toUpperCase(word.charAt(0)) + word.substring(1));
    }
    return capitalized.toString().trim();
  }

}

例子:

String sourceName = new Capitalize("this is a test"). get资本化();

sourceName将是“This Is A Test”

我使用下面的函数。我认为它在性能上更快。

public static String capitalize(String text){
    String c = (text != null)? text.trim() : "";
    String[] words = c.split(" ");
    String result = "";
    for(String w : words){
        result += (w.length() > 1? w.substring(0, 1).toUpperCase(Locale.US) + w.substring(1, w.length()).toLowerCase(Locale.US) : w) + " ";
    }
    return result.trim();
}