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
这是我做的另一种方法
StringBuilder str=new StringBuilder("pirai sudie test test");
str.setCharAt(0,Character.toUpperCase(str.charAt(0)));
for(int i=str.length()-1;i>=0;i--)
{
if(Character.isSpaceChar(str.charAt(i)))
str.setCharAt(i+1,Character.toUpperCase(str.charAt(i+1)));
}
System.out.println(str);
其他回答
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。
以下方法将所有字母转换为大写/小写，取决于它们靠近空格或其他特殊字符的位置。
public static String capitalizeString(String string) {
char[] chars = string.toLowerCase().toCharArray();
boolean found = false;
for (int i = 0; i < chars.length; i++) {
if (!found && Character.isLetter(chars[i])) {
chars[i] = Character.toUpperCase(chars[i]);
found = true;
} else if (Character.isWhitespace(chars[i]) || chars[i]=='.' || chars[i]=='\'') { // You can add other chars here
found = false;
}
}
return String.valueOf(chars);
}
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();
}
下面是这个问题的Kotlin版本:
fun capitalizeFirstLetterOfEveryWord(text: String): String
{
if (text.isEmpty() || text.isBlank())
{
return ""
}
if (text.length == 1)
{
return Character.toUpperCase(text[0]).toString()
}
val textArray = text.split(" ")
val stringBuilder = StringBuilder()
for ((index, item) in textArray.withIndex())
{
// If item is empty string, continue to next item
if (item.isEmpty())
{
continue
}
stringBuilder
.append(Character.toUpperCase(item[0]))
// If the item has only one character then continue to next item because we have already capitalized it.
if (item.length == 1)
{
continue
}
for (i in 1 until item.length)
{
stringBuilder
.append(Character.toLowerCase(item[i]))
}
if (index < textArray.lastIndex)
{
stringBuilder
.append(" ")
}
}
return stringBuilder.toString()
}
worddutil .capitalize(str) (from apache common -text)
(注意:如果你需要“fOO BAr”变成“fOO BAr”，那么用大写的(..)代替)
