blocks|key|924984|text|如果您只想大写名为input的字符串的第一个字母，而不使用其他字符：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|924985|String+output+=+input.substring(0,+1).toUpperCase()+%2B+input.substring(1);|code-block|syntax|javascript|924986|现在output将拥有您想要的东西。在使用它之前，请检查您的input是否至少有一个字符，否则您将得到一个异常。|924987|entityMap^0|9|5|0|0|2|6|U|5|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|X|8|@]|D|@]|E|$]]]|N|$]]

If you only want to capitalize the first letter of a string named <code>input</code> and leave the rest alone:

<pre><code>String output = input.substring(0, 1).toUpperCase() + input.substring(1);
</code></pre>

Now <code>output</code> will have what you want. Check that your <code>input</code> is at least one character long before using this, otherwise you'll get an exception.

blocks|key|708700|text|public+String+capitalizeFirstLetter(String+original)+{
++++if+(original+==+null+%7C%7C+original.length()+==+0)+{
++++++++return+original;
++++}
++++return+original.substring(0,+1).toUpperCase()+%2B+original.substring(1);
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|708701|只是..。一个完整的解决方案，我看到它只是将其他人最终发布的内容合并在一起。|unstyled|708702|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>public String capitalizeFirstLetter(String original) {
 if (original == null || original.length() == 0) {
 return original;
 }
 return original.substring(0, 1).toUpperCase() + original.substring(1);
}
</code></pre>

Just... a complete solution, I see it kind of just ended up combining what everyone else ended up posting =P.

blocks|key|925100|text|最简单的方法是使用org.apache.commons.lang.StringUtils类|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|925101|StringUtils.capitalize(Str);|925102|entityMap^0|9|Z|0|0|S|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

Simplest way is to use <code>org.apache.commons.lang.StringUtils</code> class

<code>StringUtils.capitalize(Str);</code>

blocks|key|708799|text|String+sentence+=+"ToDAY+++WeAthEr+++GREat";++++
public+static+String+upperCaseWords(String+sentence)+{
++++++++String+words[]+=+sentence.replaceAll("\\s%2B",+"+").trim().split("+");
++++++++String+newSentence+=+"";
++++++++for+(String+word+:+words)+{
++++++++++++for+(int+i+=+0;+i+<+word.length();+i%2B%2B)
++++++++++++++++newSentence+=+newSentence+%2B+((i+==+0)+?+word.substring(i,+i+%2B+1).toUpperCase():+
++++++++++++++++++++(i+!=+word.length()+-+1)+?+word.substring(i,+i+%2B+1).toLowerCase()+:+word.substring(i,+i+%2B+1).toLowerCase().toLowerCase()+%2B+"+");
++++++++}

++++++++return+newSentence;
++++}
//Today+Weather+Great|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|708800|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>String sentence = "ToDAY WeAthEr GREat"; 
public static String upperCaseWords(String sentence) {
 String words[] = sentence.replaceAll("\\s+", " ").trim().split(" ");
 String newSentence = "";
 for (String word : words) {
 for (int i = 0; i &lt; word.length(); i++)
 newSentence = newSentence + ((i == 0) ? word.substring(i, i + 1).toUpperCase(): 
 (i != word.length() - 1) ? word.substring(i, i + 1).toLowerCase() : word.substring(i, i + 1).toLowerCase().toLowerCase() + " ");
 }

 return newSentence;
 }
//Today Weather Great
</code></pre>

blocks|key|708808|text|StringUtils.capitalize(str)|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|708809|来自apache+commons-lang。|708810|entityMap|0|LINK|mutability|MUTABLE|url|https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html#capitalize-java.lang.String-|1|https://commons.apache.org/proper/commons-lang/^0|0|R|0|R|0|0|2|J|1|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@$9|Y|A|Z|1|10]]|E|$]]|$1|H|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]|P|$5|K|L|M|E|$N|Q]]]]

<a href="https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html#capitalize-java.lang.String-" rel="noreferrer"><code>StringUtils.capitalize(str)</code></a>

from <a href="https://commons.apache.org/proper/commons-lang/" rel="noreferrer">apache commons-lang</a>.

blocks|key|925079|text|String+s=t.getText().trim();
int+l=s.length();
char+c=Character.toUpperCase(s.charAt(0));
s=c%2Bs.substring(1);
for(int+i=1;+i<l;+i%2B%2B)
++++{
++++++++if(s.charAt(i)=='+')
++++++++{
++++++++++++c=Character.toUpperCase(s.charAt(i%2B1));
++++++++++++s=s.substring(0,+i)+%2B+c+%2B+s.substring(i%2B2);
++++++++}
++++}
++++t.setText(s);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|925080|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>String s=t.getText().trim();
int l=s.length();
char c=Character.toUpperCase(s.charAt(0));
s=c+s.substring(1);
for(int i=1; i&lt;l; i++)
 {
 if(s.charAt(i)==' ')
 {
 c=Character.toUpperCase(s.charAt(i+1));
 s=s.substring(0, i) + c + s.substring(i+2);
 }
 }
 t.setText(s);
</code></pre>

blocks|key|924929|text|这就是你的想法(希望这能给你灵感)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|924930|/*************************************************************************
+*++Compilation:++javac+Capitalize.java
+*++Execution:++++java+Capitalize+<+input.txt
+*+
+*++Read+in+a+sequence+of+words+from+standard+input+and+capitalize+each
+*++one+(make+first+letter+uppercase;+make+rest+lowercase).
+*
+*++%25+java+Capitalize
+*++now+is+the+time+for+all+good+
+*++Now+Is+The+Time+For+All+Good+
+*++to+be+or+not+to+be+that+is+the+question
+*++To+Be+Or+Not+To+Be+That+Is+The+Question+
+*
+*++Remark:+replace+sequence+of+whitespace+with+a+single+space.
+*
+*************************************************************************/

public+class+Capitalize+{

++++public+static+String+capitalize(String+s)+{
++++++++if+(s.length()+==+0)+return+s;
++++++++return+s.substring(0,+1).toUpperCase()+%2B+s.substring(1).toLowerCase();
++++}

++++public+static+void+main(String[]+args)+{
++++++++while+(!StdIn.isEmpty())+{
++++++++++++String+line+=+StdIn.readLine();
++++++++++++String[]+words+=+line.split("\\s");
++++++++++++for+(String+s+:+words)+{
++++++++++++++++StdOut.print(capitalize(s)+%2B+"+");
++++++++++++}
++++++++++++StdOut.println();
++++++++}
++++}

}|code-block|syntax|javascript|924931|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here you go (hope this give you the idea):

<pre><code>/*************************************************************************
 * Compilation: javac Capitalize.java
 * Execution: java Capitalize &lt; input.txt
 * 
 * Read in a sequence of words from standard input and capitalize each
 * one (make first letter uppercase; make rest lowercase).
 *
 * % java Capitalize
 * now is the time for all good 
 * Now Is The Time For All Good 
 * to be or not to be that is the question
 * To Be Or Not To Be That Is The Question 
 *
 * Remark: replace sequence of whitespace with a single space.
 *
 *************************************************************************/

public class Capitalize {

 public static String capitalize(String s) {
 if (s.length() == 0) return s;
 return s.substring(0, 1).toUpperCase() + s.substring(1).toLowerCase();
 }

 public static void main(String[] args) {
 while (!StdIn.isEmpty()) {
 String line = StdIn.readLine();
 String[] words = line.split("\\s");
 for (String s : words) {
 StdOut.print(capitalize(s) + " ");
 }
 StdOut.println();
 }
 }

}
</code></pre>

blocks|key|708858|text|它很简单，只需要一行代码就可以了。如果为String+A+=+scanner.nextLine();，则需要这样写才能显示第一个字母大写的字符串。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|708859|System.out.println(A.substring(0,+1).toUpperCase()+%2B+A.substring(1));|708860|现在就完成了。|708861|entityMap^0|K|U|0|0|1X|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|R|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|K|$]]

Its simple only one line code is needed for this.
if <code>String A = scanner.nextLine();</code>
then you need to write this to display the string with this first letter capitalized.

<code>System.out.println(A.substring(0, 1).toUpperCase() + A.substring(1));</code>

And its done now.

blocks|key|709301|text|如果您只想大写第一个字母，则可以使用以下代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|709302|String+output+=+input.substring(0,+1).toUpperCase()+%2B+input.substring(1);|code-block|syntax|javascript|709303|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

if you only want to capitalize the first letter then the below code can be used 

<pre><code>String output = input.substring(0, 1).toUpperCase() + input.substring(1);
</code></pre>

blocks|key|709338|text|实际上，在这种情况下，如果您避免使用%2B运算符，而使用concat()，您将获得最佳性能。这是合并2个字符串的最佳选择(虽然对于很多字符串来说不是很好)。在这种情况下，代码将如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|709339|String+output+=+input.substring(0,+1).toUpperCase().concat(input.substring(1));|code-block|syntax|javascript|709340|entityMap^0|I|1|Q|8|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

Actually, you will get the best performance if you avoid <code>+</code> operator and use <code>concat()</code> in this case. It is the best option for merging just 2 strings (not so good for many strings though). In that case the code would look like this:

<pre><code>String output = input.substring(0, 1).toUpperCase().concat(input.substring(1));
</code></pre>

blocks|key|925114|text|使用StringTokenizer类的示例：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|925115|String+st+=+"++hello+all+students";
String+st1;
char+f;
String+fs="";
StringTokenizer+a=+new+StringTokenizer(st);
while(a.hasMoreTokens()){+++
++++++++st1=a.nextToken();
++++++++f=Character.toUpperCase(st1.charAt(0));
++++++++fs%2B=f%2B+st1.substring(1);
++++++++System.out.println(fs);
}+|code-block|syntax|javascript|925116|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Example using StringTokenizer class :

<pre><code>String st = " hello all students";
String st1;
char f;
String fs="";
StringTokenizer a= new StringTokenizer(st);
while(a.hasMoreTokens()){ 
 st1=a.nextToken();
 f=Character.toUpperCase(st1.charAt(0));
 fs+=f+ st1.substring(1);
 System.out.println(fs);
} 
</code></pre>

blocks|key|708985|text|将所有内容加在一起，在字符串的开头修剪额外的空白是一个好主意。否则，.substring(0,1).toUpperCase将尝试大写空白。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|708986|++++public+String+capitalizeFirstLetter(String+original)+{
++++++++if+(original+==+null+%7C%7C+original.length()+==+0)+{
++++++++++++return+original;
++++++++}
++++++++return+original.trim().substring(0,+1).toUpperCase()+%2B+original.substring(1);
++++}|code-block|syntax|javascript|708987|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Adding everything together, it is a good idea to trim for extra white space at beginning of string. Otherwise, .substring(0,1).toUpperCase will try to capitalize a white space.

<pre><code> public String capitalizeFirstLetter(String original) {
 if (original == null || original.length() == 0) {
 return original;
 }
 return original.trim().substring(0, 1).toUpperCase() + original.substring(1);
 }
</code></pre>

blocks|key|925413|text|public+static+String+capitalize(String+str){
++++++++String[]+inputWords+=+str.split("+");
++++++++String+outputWords+=+"";
++++++++for+(String+word+:+inputWords){
++++++++++++if+(!word.isEmpty()){
++++++++++++++++outputWords+=+outputWords+%2B+"+"%2BStringUtils.capitalize(word);
++++++++++++}
++++++++}
++++++++return+outputWords;
++++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|925414|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>public static String capitalize(String str){
 String[] inputWords = str.split(" ");
 String outputWords = "";
 for (String word : inputWords){
 if (!word.isEmpty()){
 outputWords = outputWords + " "+StringUtils.capitalize(word);
 }
 }
 return outputWords;
 }
</code></pre>

blocks|key|709282|text|即使是“简单”的代码，我也会使用库。问题不在于代码本身，而在于已经存在的覆盖异常情况的测试用例。这可以是null、空字符串或其他语言的字符串。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|709283|单词操作部分已经从Apache+Commons+Lang中移出。它现在被放置在Apache+Commons+Text中。通过https://search.maven.org/artifact/org.apache.commons/commons-text获取。|709284|您可以从Apache+Commons文本中使用WordUtils.capitalize(String+str)。它比你所要求的更强大。它还可以利用fulle+(例如，修复"oNe+tousand+only")。|709285|因为它可以处理完整的文本，所以必须告诉它只将第一个单词大写。|709286|WordUtils.capitalize("one+thousand+only",+new+char[0]);|code-block|syntax|javascript|709287|完整的JUnit类，可以使用以下功能：|709288|package+io.github.koppor;

import+org.apache.commons.text.WordUtils;
import+org.junit.jupiter.api.Test;

import+static+org.junit.jupiter.api.Assertions.*;

class+AppTest+{

++@Test
++void+test()+{
++++assertEquals("One+thousand+only",+WordUtils.capitalize("one+thousand+only",+new+char[0]));
++}

}|709289|entityMap|0|LINK|mutability|MUTABLE|url|http://commons.apache.org/proper/commons-text/|1|https://search.maven.org/artifact/org.apache.commons/commons-text|2|http://commons.apache.org/proper/commons-text/apidocs/index.html^0|1G|4|0|13|J|0|1Q|1T|1|0|2D|I|N|W|2|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@$9|17|A|18|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|19|8|@]|D|@$9|1A|A|1B|1|1C]|$9|1D|A|1E|1|1F]]|E|$]]|$1|H|3|I|5|6|7|1G|8|@$9|1H|A|1I|B|C]]|D|@$9|1J|A|1K|1|1L]]|E|$]]|$1|J|3|K|5|6|7|1M|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|1N|8|@]|D|@]|E|$O|P]]|$1|Q|3|R|5|6|7|1O|8|@]|D|@]|E|$]]|$1|S|3|T|5|N|7|1P|8|@]|D|@]|E|$O|P]]|$1|U|3|-4|5|6|7|1Q|8|@]|D|@]|E|$]]]|V|$W|$5|X|Y|Z|E|$10|11]]|12|$5|X|Y|Z|E|$10|13]]|14|$5|X|Y|Z|E|$10|15]]]]

Even for "simple" code, I would use libraries. The thing is not the code per se, but the already existing test cases covering exceptional cases. This could be <code>null</code>, empty strings, strings in other languages.

The word manipulation part has been moved out ouf Apache Commons Lang. It is now placed in <a href="http://commons.apache.org/proper/commons-text/" rel="nofollow noreferrer">Apache Commons Text</a>. Get it via <a href="https://search.maven.org/artifact/org.apache.commons/commons-text" rel="nofollow noreferrer">https://search.maven.org/artifact/org.apache.commons/commons-text</a>.

You can use <a href="http://commons.apache.org/proper/commons-text/apidocs/index.html" rel="nofollow noreferrer">WordUtils.capitalize(String str)</a> from Apache Commons Text. It is more powerful than you asked for. It can also capitalize fulle (e.g., fixing <code>"oNe tousand only"</code>).

Since it works on complete text, one has to tell it to capitalize only the first word. 

<pre class="lang-java prettyprint-override"><code>WordUtils.capitalize("one thousand only", new char[0]);
</code></pre>

Full JUnit class to enable playing with the functionality:

<pre class="lang-java prettyprint-override"><code>package io.github.koppor;

import org.apache.commons.text.WordUtils;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

class AppTest {

 @Test
 void test() {
 assertEquals("One thousand only", WordUtils.capitalize("one thousand only", new char[0]));
 }

}
</code></pre>

blocks|key|708819|text|使用以下命令：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|708820|char[]+chars+=+{Character.toUpperCase(A.charAt(0)),+
Character.toUpperCase(B.charAt(0))};
String+a1+=+chars[0]+%2B+A.substring(1);
String+b1+=+chars[1]+%2B+B.substring(1);|code-block|syntax|javascript|708821|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Use this:

<pre><code>char[] chars = {Character.toUpperCase(A.charAt(0)), 
Character.toUpperCase(B.charAt(0))};
String a1 = chars[0] + A.substring(1);
String b1 = chars[1] + B.substring(1);
</code></pre>

blocks|key|709076|text|给定input字符串：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|709077|Character.toUpperCase(input.charAt(0))+%2B+input.substring(1).toLowerCase()|code-block|syntax|javascript|709078|entityMap^0|2|5|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Given the <code>input</code> string:

<pre><code>Character.toUpperCase(input.charAt(0)) + input.substring(1).toLowerCase()
</code></pre>

blocks|key|925400|text|您可以尝试以下代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|925401|public+string+capitalize(str)+{
++++String[]+array+=+str.split("+");
++++String+newStr;
++++for(int+i+=+0;+i+<+array.length;+i%2B%2B)+{
++++++++newStr+%2B=+array[i].substring(0,1).toUpperCase()+%2B+array[i].substring(1)+%2B+"+";
++++}
++++return+newStr.trim();
}|code-block|syntax|javascript|925402|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can try the following code:

<pre><code>public string capitalize(str) {
 String[] array = str.split(" ");
 String newStr;
 for(int i = 0; i &lt; array.length; i++) {
 newStr += array[i].substring(0,1).toUpperCase() + array[i].substring(1) + " ";
 }
 return newStr.trim();
}
</code></pre>

blocks|key|925447|text|无论inputString的值是多少，以下代码都将提供相同的一致输出：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|925448|if(StringUtils.isNotBlank(inputString))+{
++++inputString+=+StringUtils.capitalize(inputString.toLowerCase());
}|code-block|syntax|javascript|925449|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The following will give you the same consistent output regardless of the value of your inputString:

<pre><code>if(StringUtils.isNotBlank(inputString)) {
 inputString = StringUtils.capitalize(inputString.toLowerCase());
}
</code></pre>

blocks|key|925512|text|1.使用String的substring()方法|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|925513|public+static+String+capitalize(String+str)+{
++++if(str==+null+%7C%7C+str.isEmpty())+{
++++++++return+str;
++++}

++++return+str.substring(0,+1).toUpperCase()+%2B+str.substring(1);
}|code-block|syntax|javascript|925514|现在只需调用capitalize()方法将字符串的第一个字母转换为大写：|925515|System.out.println(capitalize("stackoverflow"));+//+Stackoverflow
System.out.println(capitalize("heLLo"));+//+HeLLo
System.out.println(capitalize(null));+//+null|925516|2.+Apache+Commons+Lang|925517|Commons+Lang中的StringUtils类提供了也可用于此目的的capitalize()方法：|925518|System.out.println(StringUtils.capitalize("apache+commons"));+//+Apache+commons
System.out.println(StringUtils.capitalize("heLLO"));+//+HeLLO
System.out.println(StringUtils.uncapitalize(null));+//+null|925519|将以下依赖项添加到您的pom.xml文件(仅限Maven+)：|925520|<dependency>
++++<groupId>org.apache.commons</groupId>
++++<artifactId>commons-lang3</artifactId>
++++<version>3.9</version>
</dependency>|925521|下面是详细解释这两种方法的an+article。|925522|entityMap|0|LINK|mutability|MUTABLE|url|https://attacomsian.com/blog/capitalize-first-letter-of-string-java^0|B|B|0|0|6|C|0|0|0|E|B|11|C|0|0|B|7|0|0|D|A|0|0^^$0|@$1|2|3|4|5|6|7|18|8|@$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|1B|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1C|8|@$9|1D|A|1E|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|1F|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1G|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1H|8|@$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]]|D|@]|E|$]]|$1|S|3|T|5|H|7|1M|8|@]|D|@]|E|$I|J]]|$1|U|3|V|5|6|7|1N|8|@$9|1O|A|1P|B|C]]|D|@]|E|$]]|$1|W|3|X|5|H|7|1Q|8|@]|D|@]|E|$I|J]]|$1|Y|3|Z|5|6|7|1R|8|@]|D|@$9|1S|A|1T|1|1U]]|E|$]]|$1|10|3|-4|5|6|7|1V|8|@]|D|@]|E|$]]]|11|$12|$5|13|14|15|E|$16|17]]]]

<h3>1. Using String's <code>substring()</code> Method</h3>

<pre class="lang-java prettyprint-override"><code>public static String capitalize(String str) {
 if(str== null || str.isEmpty()) {
 return str;
 }

 return str.substring(0, 1).toUpperCase() + str.substring(1);
}
</code></pre>

Now just call the <code>capitalize()</code> method to convert the first letter of a string to uppercase:

<pre class="lang-java prettyprint-override"><code>System.out.println(capitalize("stackoverflow")); // Stackoverflow
System.out.println(capitalize("heLLo")); // HeLLo
System.out.println(capitalize(null)); // null
</code></pre>

<h3>2. Apache Commons Lang</h3>

The <code>StringUtils</code> class from Commons Lang provides the <code>capitalize()</code> method that can also be used for this purpose:

<pre class="lang-java prettyprint-override"><code>System.out.println(StringUtils.capitalize("apache commons")); // Apache commons
System.out.println(StringUtils.capitalize("heLLO")); // HeLLO
System.out.println(StringUtils.uncapitalize(null)); // null
</code></pre>

Add the following dependency to your <code>pom.xml</code> file (for Maven only):

<pre class="lang-xml prettyprint-override"><code>&lt;dependency&gt;
 &lt;groupId&gt;org.apache.commons&lt;/groupId&gt;
 &lt;artifactId&gt;commons-lang3&lt;/artifactId&gt;
 &lt;version&gt;3.9&lt;/version&gt;
&lt;/dependency&gt;
</code></pre>

Here is <a href="https://attacomsian.com/blog/capitalize-first-letter-of-string-java" rel="nofollow noreferrer">an article</a> that explains these two approaches in detail.

blocks|key|708939|text|class+Test+{
+++++public+static+void+main(String[]+args)+{
++++++++String+newString="";
++++++++String+test="Hii+lets+cheCk+for+BEING+String";++
++++++++String[]+splitString+=+test.split("+");
++++++++for(int+i=0;+i<splitString.length;+i%2B%2B){
++++++++++++newString=+newString%2B+splitString[i].substring(0,1).toUpperCase()+
++++++++++++++++++++%2B+splitString[i].substring(1,splitString[i].length()).toLowerCase()%2B"+";
++++++++}
++++++++System.out.println("the+new+String+is+"%2BnewString);
++++}
+}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|708940|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>class Test {
 public static void main(String[] args) {
 String newString="";
 String test="Hii lets cheCk for BEING String"; 
 String[] splitString = test.split(" ");
 for(int i=0; i&lt;splitString.length; i++){
 newString= newString+ splitString[i].substring(0,1).toUpperCase() 
 + splitString[i].substring(1,splitString[i].length()).toLowerCase()+" ";
 }
 System.out.println("the new String is "+newString);
 }
 }
</code></pre>

Example strings

<pre><code>one thousand only
two hundred
twenty
seven
</code></pre>

How do I change the first character of a string in capital letter and not change the case of any of the other letters?

After the change it should be:

<pre><code>One thousand only
Two hundred
Twenty
Seven
</code></pre>

Note: I don't want to use the apache.commons.lang.WordUtils to do this.

How to capitalize the first letter of word in a string using Java?

示例字符串one thousand onlytwo hundredtwentyseven如何更改字符串的第一个大写字母，而不更改其他任何字母的大小写？更改后，它应该是：One thousand onlyTwo hundredTwentySeven注意:我不想使用apache.commons.lang.WordUtils来做这件事。

问如何使用Java将字符串中单词的第一个字母大写？
EN

回答 20

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问如何使用Java将字符串中单词的第一个字母大写？EN

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问如何使用Java将字符串中单词的第一个字母大写？
EN