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
String toBeCapped = "i want this sentence capitalized";
String[] tokens = toBeCapped.split("\\s");
toBeCapped = "";
for(int i = 0; i < tokens.length; i++){
char capLetter = Character.toUpperCase(tokens[i].charAt(0));
toBeCapped += " " + capLetter + tokens[i].substring(1);
}
toBeCapped = toBeCapped.trim();
其他回答
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)
因为没有人使用regexp，所以我们使用regexp。这个解决方案只是为了好玩。:)(更新:实际上我刚刚发现有一个regexp的答案，无论如何，我想把这个答案留在原地，因为它更好看:)):
public class Capitol
{
public static String now(String str)
{
StringBuffer b = new StringBuffer();
Pattern p = Pattern.compile("\\b(\\w){1}");
Matcher m = p.matcher(str);
while (m.find())
{
String s = m.group(1);
m.appendReplacement(b, s.toUpperCase());
}
m.appendTail(b);
return b.toString();
}
}
使用
Capitol.now("ab cd"));
Capitol.now("winnie the Pooh"));
Capitol.now("please talk loudly!"));
Capitol.now("miles o'Brien"));
String toBeCapped = "i want this sentence capitalized";
String[] tokens = toBeCapped.split("\\s");
toBeCapped = "";
for(int i = 0; i < tokens.length; i++){
char capLetter = Character.toUpperCase(tokens[i].charAt(0));
toBeCapped += " " + capLetter + tokens[i].substring(1);
}
toBeCapped = toBeCapped.trim();
来自Java 9+
你可以像这样使用String::replaceAll:
public static void upperCaseAllFirstCharacter(String text) {
String regex = "\\b(.)(.*?)\\b";
String result = Pattern.compile(regex).matcher(text).replaceAll(
matche -> matche.group(1).toUpperCase() + matche.group(2)
);
System.out.println(result);
}
例子:
upperCaseAllFirstCharacter("hello this is Just a test");
输出
Hello This Is Just A Test
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()
}
