How to capitalize the first character of each word in a string

Question

Is there a function built into Java that capitalizes the first character of each word in a String, and does not affect the others?

Examples:

• jon skeet -> Jon Skeet
• miles o'Brien -> Miles O'Brien (B remains capital, this rules out Title Case)
• old mcdonald -> Old Mcdonald*

*(Old McDonald would be find too, but I don't expect it to be THAT smart.)

A quick look at the Java String Documentation reveals only toUpperCase() and toLowerCase(), which of course do not provide the desired behavior. Naturally, Google results are dominated by those two functions. It seems like a wheel that must have been invented already, so it couldn't hurt to ask so I can use it in the future.

Answer 1

WordUtils.capitalize(str) (from apache commons-text)

(Note: if you need "fOO BAr" to become "Foo Bar", then use capitalizeFully(..) instead)

Answer 2

If you're only worried about the first letter of the first word being capitalized:

private String capitalize(final String line) {
   return Character.toUpperCase(line.charAt(0)) + line.substring(1);
}

Answer 3

The following method converts all the letters into upper/lower case, depending on their position near a space or other special chars.

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);
}

Answer 4

Try this very simple way

example givenString="ram is good boy"

public static String toTitleCase(String givenString) {
    String[] arr = givenString.split(" ");
    StringBuffer sb = new StringBuffer();

    for (int i = 0; i < arr.length; i++) {
        sb.append(Character.toUpperCase(arr[i].charAt(0)))
            .append(arr[i].substring(1)).append(" ");
    }          
    return sb.toString().trim();
}  

Output will be: Ram Is Good Boy

Answer 5

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();

Answer 6

I've written a small Class to capitalize all the words in a String.

Optional multiple delimiters, each one with its behavior (capitalize before, after, or both, to handle cases like O'Brian);

Optional Locale;

Don't breaks with Surrogate Pairs.

LIVE DEMO

Output:

====================================
 SIMPLE USAGE
====================================
Source: cApItAlIzE this string after WHITE SPACES
Output: Capitalize This String After White Spaces

====================================
 SINGLE CUSTOM-DELIMITER USAGE
====================================
Source: capitalize this string ONLY before'and''after'''APEX
Output: Capitalize this string only beforE'AnD''AfteR'''Apex

====================================
 MULTIPLE CUSTOM-DELIMITER USAGE
====================================
Source: capitalize this string AFTER SPACES, BEFORE'APEX, and #AFTER AND BEFORE# NUMBER SIGN (#)
Output: Capitalize This String After Spaces, BeforE'apex, And #After And BeforE# Number Sign (#)

====================================
 SIMPLE USAGE WITH CUSTOM LOCALE
====================================
Source: Uniforming the first and last vowels (different kind of 'i's) of the Turkish word D[İ]YARBAK[I]R (DİYARBAKIR) 
Output: Uniforming The First And Last Vowels (different Kind Of 'i's) Of The Turkish Word D[i]yarbak[i]r (diyarbakir) 

====================================
 SIMPLE USAGE WITH A SURROGATE PAIR 
====================================
Source: ab 𐐂c de à
Output: Ab 𐐪c De À

Note: first letter will always be capitalized (edit the source if you don't want that).

Please share your comments and help me to found bugs or to improve the code...

Code:

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Locale;

public class WordsCapitalizer {

    public static String capitalizeEveryWord(String source) {
        return capitalizeEveryWord(source,null,null);
    }

    public static String capitalizeEveryWord(String source, Locale locale) {
        return capitalizeEveryWord(source,null,locale);
    }

    public static String capitalizeEveryWord(String source, List<Delimiter> delimiters, Locale locale) {
        char[] chars; 

        if (delimiters == null || delimiters.size() == 0)
            delimiters = getDefaultDelimiters();                

        // If Locale specified, i18n toLowerCase is executed, to handle specific behaviors (eg. Turkish dotted and dotless 'i')
        if (locale!=null)
            chars = source.toLowerCase(locale).toCharArray();
        else 
            chars = source.toLowerCase().toCharArray();

        // First charachter ALWAYS capitalized, if it is a Letter.
        if (chars.length>0 && Character.isLetter(chars[0]) && !isSurrogate(chars[0])){
            chars[0] = Character.toUpperCase(chars[0]);
        }

        for (int i = 0; i < chars.length; i++) {
            if (!isSurrogate(chars[i]) && !Character.isLetter(chars[i])) {
                // Current char is not a Letter; gonna check if it is a delimitrer.
                for (Delimiter delimiter : delimiters){
                    if (delimiter.getDelimiter()==chars[i]){
                        // Delimiter found, applying rules...                       
                        if (delimiter.capitalizeBefore() && i>0 
                            && Character.isLetter(chars[i-1]) && !isSurrogate(chars[i-1]))
                        {   // previous character is a Letter and I have to capitalize it
                            chars[i-1] = Character.toUpperCase(chars[i-1]);
                        }
                        if (delimiter.capitalizeAfter() && i<chars.length-1 
                            && Character.isLetter(chars[i+1]) && !isSurrogate(chars[i+1]))
                        {   // next character is a Letter and I have to capitalize it
                            chars[i+1] = Character.toUpperCase(chars[i+1]);
                        }
                        break;
                    }
                } 
            }
        }
        return String.valueOf(chars);
    }


    private static boolean isSurrogate(char chr){
        // Check if the current character is part of an UTF-16 Surrogate Pair.  
        // Note: not validating the pair, just used to bypass (any found part of) it.
        return (Character.isHighSurrogate(chr) || Character.isLowSurrogate(chr));
    }       

    private static List<Delimiter> getDefaultDelimiters(){
        // If no delimiter specified, "Capitalize after space" rule is set by default. 
        List<Delimiter> delimiters = new ArrayList<Delimiter>();
        delimiters.add(new Delimiter(Behavior.CAPITALIZE_AFTER_MARKER, ' '));
        return delimiters;
    } 

    public static class Delimiter {
        private Behavior behavior;
        private char delimiter;

        public Delimiter(Behavior behavior, char delimiter) {
            super();
            this.behavior = behavior;
            this.delimiter = delimiter;
        }

        public boolean capitalizeBefore(){
            return (behavior.equals(Behavior.CAPITALIZE_BEFORE_MARKER)
                    || behavior.equals(Behavior.CAPITALIZE_BEFORE_AND_AFTER_MARKER));
        }

        public boolean capitalizeAfter(){
            return (behavior.equals(Behavior.CAPITALIZE_AFTER_MARKER)
                    || behavior.equals(Behavior.CAPITALIZE_BEFORE_AND_AFTER_MARKER));
        }

        public char getDelimiter() {
            return delimiter;
        }
    }

    public static enum Behavior {
        CAPITALIZE_AFTER_MARKER(0),
        CAPITALIZE_BEFORE_MARKER(1),
        CAPITALIZE_BEFORE_AND_AFTER_MARKER(2);                      

        private int value;          

        private Behavior(int value) {
            this.value = value;
        }

        public int getValue() {
            return value;
        }           
    } 

Answer 7

I made a solution in Java 8 that is IMHO more readable.

public String firstLetterCapitalWithSingleSpace(final String words) {
    return Stream.of(words.trim().split("\\s"))
    .filter(word -> word.length() > 0)
    .map(word -> word.substring(0, 1).toUpperCase() + word.substring(1))
    .collect(Collectors.joining(" "));
}

The Gist for this solution can be found here: https://gist.github.com/Hylke1982/166a792313c5e2df9d31

Answer 8

Using org.apache.commons.lang.StringUtils makes it very simple.

capitalizeStr = StringUtils.capitalize(str);

Answer 9

With this simple code:

String example="hello";

example=example.substring(0,1).toUpperCase()+example.substring(1, example.length());

System.out.println(example);

Result: Hello

Answer 10

I'm using the following function. I think it is faster in performance.

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();
}

Answer 11

From Java 9+

you can use String::replaceAll like this :

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);
}

Example :

upperCaseAllFirstCharacter("hello this is Just a test");

Outputs

Hello This Is Just A Test

Answer 12

Use the Split method to split your string into words, then use the built in string functions to capitalize each word, then append together.

Pseudo-code (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

In the end string looks something like "The Sentence You Want To Apply Caps To"

Answer 13

This might be useful if you need to capitalize titles. It capitalizes each substring delimited by " ", except for specified strings such as "a" or "the". I haven't ran it yet because it's late, should be fine though. Uses Apache Commons StringUtils.join() at one point. You can substitute it with a simple loop if you wish.

private static String capitalize(String string) {
    if (string == null) return null;
    String[] wordArray = string.split(" "); // Split string to analyze word by word.
    int i = 0;
lowercase:
    for (String word : wordArray) {
        if (word != wordArray[0]) { // First word always in capital
            String [] lowercaseWords = {"a", "an", "as", "and", "although", "at", "because", "but", "by", "for", "in", "nor", "of", "on", "or", "so", "the", "to", "up", "yet"};
            for (String word2 : lowercaseWords) {
                if (word.equals(word2)) {
                    wordArray[i] = word;
                    i++;
                    continue lowercase;
                }
            }
        }
        char[] characterArray = word.toCharArray();
        characterArray[0] = Character.toTitleCase(characterArray[0]);
        wordArray[i] = new String(characterArray);
        i++;
    }
    return StringUtils.join(wordArray, " "); // Re-join string
}

Answer 14

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());
}

Answer 15

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));   

System.out.println("Enter the sentence : ");

try
{
    String str = br.readLine();
    char[] str1 = new char[str.length()];

    for(int i=0; i<str.length(); i++)
    {
        str1[i] = Character.toLowerCase(str.charAt(i));
    }

    str1[0] = Character.toUpperCase(str1[0]);
    for(int i=0;i<str.length();i++)
    {
        if(str1[i] == ' ')
        {                   
            str1[i+1] =  Character.toUpperCase(str1[i+1]);
        }
        System.out.print(str1[i]);
    }
}
catch(Exception e)
{
    System.err.println("Error: " + e.getMessage());
}

Answer 16

I decided to add one more solution for capitalizing words in a string:

• words are defined here as adjacent letter-or-digit characters;
• surrogate pairs are provided as well;
• the code has been optimized for performance; and
• it is still compact.

Function:

public static String capitalize(String string) {
  final int sl = string.length();
  final StringBuilder sb = new StringBuilder(sl);
  boolean lod = false;
  for(int s = 0; s < sl; s++) {
    final int cp = string.codePointAt(s);
    sb.appendCodePoint(lod ? Character.toLowerCase(cp) : Character.toUpperCase(cp));
    lod = Character.isLetterOrDigit(cp);
    if(!Character.isBmpCodePoint(cp)) s++;
  }
  return sb.toString();
}

Example call:

System.out.println(capitalize("An à la carte StRiNg. Surrogate pairs: 𐐪𐐪."));

Result:

An À La Carte String. Surrogate Pairs: 𐐂𐐪.

Answer 17

Use:

    String text = "jon skeet, miles o'brien, old mcdonald";

    Pattern pattern = Pattern.compile("\\b([a-z])([\\w]*)");
    Matcher matcher = pattern.matcher(text);
    StringBuffer buffer = new StringBuffer();
    while (matcher.find()) {
        matcher.appendReplacement(buffer, matcher.group(1).toUpperCase() + matcher.group(2));
    }
    String capitalized = matcher.appendTail(buffer).toString();
    System.out.println(capitalized);

Answer 18

There are many way to convert the first letter of the first word being capitalized. I have an idea. It's very simple:

public String capitalize(String str){

     /* The first thing we do is remove whitespace from string */
     String c = str.replaceAll("\\s+", " ");
     String s = c.trim();
     String l = "";

     for(int i = 0; i < s.length(); i++){
          if(i == 0){                              /* Uppercase the first letter in strings */
              l += s.toUpperCase().charAt(i);
              i++;                                 /* To i = i + 1 because we don't need to add               
                                                    value i = 0 into string l */
          }

          l += s.charAt(i);

          if(s.charAt(i) == 32){                   /* If we meet whitespace (32 in ASCII Code is whitespace) */
              l += s.toUpperCase().charAt(i+1);    /* Uppercase the letter after whitespace */
              i++;                                 /* Yo i = i + 1 because we don't need to add
                                                   value whitespace into string l */
          }        
     }
     return l;
}

Answer 19

1. Java 8 Streams

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(" "));
}

Examples:

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

For foo bAR to Foo Bar, replace the map() method with the following:

.map(t -> t.substring(0, 1).toUpperCase() + t.substring(1).toLowerCase())

2. String.replaceAll() (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));
}

Examples:

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 Text

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

For titlecase:

System.out.println(WordUtils.capitalizeFully("fOO bAR")); // Foo Bar
System.out.println(WordUtils.capitalizeFully("sKy is BLUE!")); // Sky Is Blue!

For details, checkout this tutorial.

Answer 20

  package com.test;

 /**
   * @author Prasanth Pillai
   * @date 01-Feb-2012
   * @description : Below is the test class details
   * 
   * inputs a String from a user. Expect the String to contain spaces and    alphanumeric     characters only.
   * capitalizes all first letters of the words in the given String.
   * preserves all other characters (including spaces) in the String.
   * displays the result to the user.
   * 
   * Approach : I have followed a simple approach. However there are many string    utilities available 
   * for the same purpose. Example : WordUtils.capitalize(str) (from apache commons-lang)
   *
   */
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;

  public class Test {

public static void main(String[] args) throws IOException{
    System.out.println("Input String :\n");
    InputStreamReader converter = new InputStreamReader(System.in);
    BufferedReader in = new BufferedReader(converter);
    String inputString = in.readLine();
    int length = inputString.length();
    StringBuffer newStr = new StringBuffer(0);
    int i = 0;
    int k = 0;
    /* This is a simple approach
     * step 1: scan through the input string
     * step 2: capitalize the first letter of each word in string
     * The integer k, is used as a value to determine whether the 
     * letter is the first letter in each word in the string.
     */

    while( i < length){
        if (Character.isLetter(inputString.charAt(i))){
            if ( k == 0){
            newStr = newStr.append(Character.toUpperCase(inputString.charAt(i)));
            k = 2;
            }//this else loop is to avoid repeatation of the first letter in output string 
            else {
            newStr = newStr.append(inputString.charAt(i));
            }
        } // for the letters which are not first letter, simply append to the output string. 
        else {
            newStr = newStr.append(inputString.charAt(i));
            k=0;
        }
        i+=1;           
    }
    System.out.println("new String ->"+newStr);
    }
}

Answer 21

Here is a simple function

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();
}

Answer 22

This is just another way of doing it:

private String capitalize(String line)
{
    StringTokenizer token =new StringTokenizer(line);
    String CapLine="";
    while(token.hasMoreTokens())
    {
        String tok = token.nextToken().toString();
        CapLine += Character.toUpperCase(tok.charAt(0))+ tok.substring(1)+" ";        
    }
    return CapLine.substring(0,CapLine.length()-1);
}

Answer 23

Reusable method for intiCap:

    public class YarlagaddaSireeshTest{

    public static void main(String[] args) {
        String FinalStringIs = "";
        String testNames = "sireesh yarlagadda test";
        String[] name = testNames.split("\\s");

        for(String nameIs :name){
            FinalStringIs += getIntiCapString(nameIs) + ",";
        }
        System.out.println("Final Result "+ FinalStringIs);
    }

    public static String getIntiCapString(String param) {
        if(param != null && param.length()>0){          
            char[] charArray = param.toCharArray(); 
            charArray[0] = Character.toUpperCase(charArray[0]); 
            return new String(charArray); 
        }
        else {
            return "";
        }
    }
}

Answer 24

Here is my solution.

I ran across this problem tonight and decided to search it. I found an answer by Neelam Singh that was almost there, so I decided to fix the issue (broke on empty strings) and caused a system crash.

The method you are looking for is named capString(String s) below. It turns "It's only 5am here" into "It's Only 5am Here".

The code is pretty well commented, so enjoy.

package com.lincolnwdaniel.interactivestory.model;

    public class StringS {

    /**
     * @param s is a string of any length, ideally only one word
     * @return a capitalized string.
     * only the first letter of the string is made to uppercase
     */
    public static String capSingleWord(String s) {
        if(s.isEmpty() || s.length()<2) {
            return Character.toUpperCase(s.charAt(0))+"";
        } 
        else {
            return Character.toUpperCase(s.charAt(0)) + s.substring(1);
        }
    }

    /**
     *
     * @param s is a string of any length
     * @return a title cased string.
     * All first letter of each word is made to uppercase
     */
    public static String capString(String s) {
        // Check if the string is empty, if it is, return it immediately
        if(s.isEmpty()){
            return s;
        }

        // Split string on space and create array of words
        String[] arr = s.split(" ");
        // Create a string buffer to hold the new capitalized string
        StringBuffer sb = new StringBuffer();

        // Check if the array is empty (would be caused by the passage of s as an empty string [i.g "" or " "],
        // If it is, return the original string immediately
        if( arr.length < 1 ){
            return s;
        }

        for (int i = 0; i < arr.length; i++) {
            sb.append(Character.toUpperCase(arr[i].charAt(0)))
                    .append(arr[i].substring(1)).append(" ");
        }
        return sb.toString().trim();
    }
}

Answer 25

For those of you using Velocity in your MVC, you can use the capitalizeFirstLetter() method from the StringUtils class.

Answer 26

String s="hi dude i                                 want apple";
    s = s.replaceAll("\\s+"," ");
    String[] split = s.split(" ");
    s="";
    for (int i = 0; i < split.length; i++) {
        split[i]=Character.toUpperCase(split[i].charAt(0))+split[i].substring(1);
        s+=split[i]+" ";
        System.out.println(split[i]);
    }
    System.out.println(s);

Answer 27

package corejava.string.intern;

import java.io.DataInputStream;

import java.util.ArrayList;

/*
 * wap to accept only 3 sentences and convert first character of each word into upper case
 */

public class Accept3Lines_FirstCharUppercase {

    static String line;
    static String words[];
    static ArrayList<String> list=new ArrayList<String>();

    /**
     * @param args
     */
    public static void main(String[] args) throws java.lang.Exception{

        DataInputStream read=new DataInputStream(System.in);
        System.out.println("Enter only three sentences");
        int i=0;
        while((line=read.readLine())!=null){
            method(line);       //main logic of the code
            if((i++)==2){
                break;
            }
        }
        display();
        System.out.println("\n End of the program");

    }

    /*
     * this will display all the elements in an array
     */
    public static void display(){
        for(String display:list){
            System.out.println(display);
        }
    }

    /*
     * this divide the line of string into words 
     * and first char of the each word is converted to upper case
     * and to an array list
     */
    public static void method(String lineParam){
        words=line.split("\\s");
        for(String s:words){
            String result=s.substring(0,1).toUpperCase()+s.substring(1);
            list.add(result);
        }
    }

}

Answer 28

If you prefer Guava...

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);
    }
}));

Answer 29

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();
}

Answer 30

The short and precise way is as follows:

String name = "test";

name = (name.length() != 0) ?name.toString().toLowerCase().substring(0,1).toUpperCase().concat(name.substring(1)): name;

--------------------
Output
--------------------
Test
T 
empty
--------------------

It works without error if you try and change the name value to the three of values. Error free.