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
使用Split方法将字符串拆分为单词，然后使用内置的字符串函数将每个单词大写，然后附加在一起。
伪代码(ish)
string = "the sentence you want to apply caps to";
words = string.split(" ")
string = ""
for(String w: words)
//This line is an easy way to capitalize a word
word = word.toUpperCase().replace(word.substring(1), word.substring(1).toLowerCase())
string += word
最后字符串看起来像这样 "你想要加大写字母的句子"
其他回答
这是一个简单的函数
public static String capEachWord(String source){
String result = "";
String[] splitString = source.split(" ");
for(String target : splitString){
result += Character.toUpperCase(target.charAt(0))
+ target.substring(1) + " ";
}
return result.trim();
}
使用Split方法将字符串拆分为单词，然后使用内置的字符串函数将每个单词大写，然后附加在一起。
伪代码(ish)
string = "the sentence you want to apply caps to";
words = string.split(" ")
string = ""
for(String w: words)
//This line is an easy way to capitalize a word
word = word.toUpperCase().replace(word.substring(1), word.substring(1).toLowerCase())
string += word
最后字符串看起来像这样 "你想要加大写字母的句子"
1. Java 8流
public static String capitalizeAll(String str) {
if (str == null || str.isEmpty()) {
return str;
}
return Arrays.stream(str.split("\\s+"))
.map(t -> t.substring(0, 1).toUpperCase() + t.substring(1))
.collect(Collectors.joining(" "));
}
例子:
System.out.println(capitalizeAll("jon skeet")); // Jon Skeet
System.out.println(capitalizeAll("miles o'Brien")); // Miles O'Brien
System.out.println(capitalizeAll("old mcdonald")); // Old Mcdonald
System.out.println(capitalizeAll(null)); // null
对于foo bAR到foo bAR，替换map()方法如下:
.map(t -> t.substring(0, 1).toUpperCase() + t.substring(1).toLowerCase())
2. 字符串()(Java 9+)
ublic static String capitalizeAll(String str) {
if (str == null || str.isEmpty()) {
return str;
}
return Pattern.compile("\\b(.)(.*?)\\b")
.matcher(str)
.replaceAll(match -> match.group(1).toUpperCase() + match.group(2));
}
例子:
System.out.println(capitalizeAll("12 ways to learn java")); // 12 Ways To Learn Java
System.out.println(capitalizeAll("i am atta")); // I Am Atta
System.out.println(capitalizeAll(null)); // null
3.Apache Commons文本
System.out.println(WordUtils.capitalize("love is everywhere")); // Love Is Everywhere
System.out.println(WordUtils.capitalize("sky, sky, blue sky!")); // Sky, Sky, Blue Sky!
System.out.println(WordUtils.capitalize(null)); // null
titlecase:
System.out.println(WordUtils.capitalizeFully("fOO bAR")); // Foo Bar
System.out.println(WordUtils.capitalizeFully("sKy is BLUE!")); // Sky Is Blue!
有关详细信息，请查看本教程。
String toUpperCaseFirstLetterOnly(String str) {
String[] words = str.split(" ");
StringBuilder ret = new StringBuilder();
for(int i = 0; i < words.length; i++) {
ret.append(Character.toUpperCase(words[i].charAt(0)));
ret.append(words[i].substring(1));
if(i < words.length - 1) {
ret.append(' ');
}
}
return ret.toString();
}
试试这个:
private String capitalizer(String word){
String[] words = word.split(" ");
StringBuilder sb = new StringBuilder();
if (words[0].length() > 0) {
sb.append(Character.toUpperCase(words[0].charAt(0)) + words[0].subSequence(1, words[0].length()).toString().toLowerCase());
for (int i = 1; i < words.length; i++) {
sb.append(" ");
sb.append(Character.toUpperCase(words[i].charAt(0)) + words[i].subSequence(1, words[i].length()).toString().toLowerCase());
}
}
return sb.toString();
}
