CODEWITHSUNDEEP
javastringuppercaselowercasecapitalization
WillfulWizard
WillfulWizard

Reputation: 5409

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

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:

*(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.

Upvotes: 474

Views: 551919

Answers (30)

Youcef LAIDANI
Youcef LAIDANI

Reputation: 59950

From Java 9+

you can use Matcher::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

Upvotes: 10

Ali Mizan
Ali Mizan

Reputation: 1922

I noticed in previous answers that referred to apache common utils, they either used the class WordUtils which is now deprecated, or they use StringUtils.capitalize() which only capitalizes the first word but not every single word in the sentence.

Here is a pure java solution to do this. Note: this will not work if there is a bit of punctuation in front of the word. Here's the function capitalizeEachWord(), but wrapped up in a main class so you can see a few basic tests cases.


import java.util.Optional;
import java.util.Objects;

class HelloWorld {
    public static void main(String[] args) {
        System.out.println(capitalizeEachWord(""));
        System.out.println(capitalizeEachWord("."));
        System.out.println(capitalizeEachWord(" ."));
        System.out.println(capitalizeEachWord(" . "));
        System.out.println(capitalizeEachWord("testing. 1 one 2 two 3 three"));
        System.out.println(capitalizeEachWord("testing. 1 one 2 two 3 three."));
        System.out.println(capitalizeEachWord("testing. 1 one 2 two 3 three "));
        System.out.println(capitalizeEachWord("testing. 1 one 2 two 3 three. "));
        System.out.println(capitalizeEachWord(" testing. 1 one 2 two 3 three"));
        System.out.println(capitalizeEachWord("!testing. 1 one 2 two 3 three."));
        System.out.println(capitalizeEachWord(" !testing. 1 one 2 two 3 three "));
        System.out.println(capitalizeEachWord(" !testing. 1 one 2 two 3 three "));
        System.out.println(capitalizeEachWord(" !testing. 1 one 2 two 3 three 4"));
    }
    
    
    private static String capitalizeEachWord(final String line) {
        return Optional.ofNullable(line)
            .filter(Objects::nonNull)
            .filter(givenLine -> givenLine.length() > 0)
            .map(givenLine -> {
                StringBuilder sb = new StringBuilder(givenLine);
                if(sb.charAt(0) != ' ') {
                    sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));
                }
                for (int i = 1; i < sb.length(); i++) {
                    if (sb.charAt(i - 1) == ' ') {
                        sb.setCharAt(i, Character.toUpperCase(sb.charAt(i)));
                    }
                }
                return sb.toString();
            })
            .orElse(line);
    }
    
    
}

resulting output:

.
 .
 . 
Testing. 1 One 2 Two 3 Three
Testing. 1 One 2 Two 3 Three.
Testing. 1 One 2 Two 3 Three 
Testing. 1 One 2 Two 3 Three. 
 Testing. 1 One 2 Two 3 Three
!testing. 1 One 2 Two 3 Three.
 !testing. 1 One 2 Two 3 Three 
 !testing. 1 One 2 Two 3 Three 
 !testing. 1 One 2 Two 3 Three 4

Upvotes: 0

Bozho
Bozho

Reputation: 596996

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

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

Upvotes: 799

Sagan
Sagan

Reputation: 112

You can also do it very simply like this and preserve any doubled and leading, trailing whitespaces 

public static String capitalizeWords(String text) {

    StringBuilder sb = new StringBuilder();
    if(text.length()>0){
        sb.append(Character.toUpperCase(text.charAt(0)));
    }
    for (int i=1; i<text.length(); i++){
        String chPrev = String.valueOf(text.charAt(i-1));
        String ch = String.valueOf(text.charAt(i));

        if(Objects.equals(chPrev, " ")){
            sb.append(ch.toUpperCase());
        }else {
            sb.append(ch);
        }

    }

    return sb.toString();

}

Upvotes: 0

attacomsian
attacomsian

Reputation: 2913

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.

Upvotes: 6

Dylan Hatch
Dylan Hatch

Reputation: 1

Heres a lil program I was using to capitalize each first letter word in every subfolder of a parent directory.

private void capitalize(String string)
{
    List<String> delimiters = new ArrayList<>();
    delimiters.add(" ");
    delimiters.add("_");

    File folder = new File(string);
    String name = folder.getName();
    String[] characters = name.split("");

    String newName = "";
    boolean capitalizeNext = false;

    for (int i = 0; i < characters.length; i++)
    {
        String character = characters[i];

        if (capitalizeNext || i == 0)
        {
            newName += character.toUpperCase();
            capitalizeNext = false;
        }
        else
        {
            if (delimiters.contains(character)) capitalizeNext = true;
            newName += character;
        }
    }

    folder.renameTo(new File(folder.getParent() + File.separator + newName));
}

Upvotes: 0

C. Solarte
C. Solarte

Reputation: 1

public static void main(String[] args) throws IOException {
    String words = "this is a test";

    System.out.println(Arrays.asList(words.split(" ")).stream().reduce("",(a, b)->(a + " " + b.substring(0, 1).toUpperCase() + b.substring(1))));


}

}

Upvotes: 0

Shubhasish Bhunia
Shubhasish Bhunia

Reputation: 223

I just want to add an alternative solution for the problem by using only Java code. No extra library 

public String Capitalize(String str) {

            String tt = "";
            String tempString = "";
            String tempName = str.trim().toLowerCase();
            String[] tempNameArr = tempName.split(" ");
            System.out.println("The size is " + tempNameArr.length);
            if (tempNameArr.length > 1) {
                for (String t : tempNameArr) {
                    tt += Capitalize(t);
                    tt += " ";
                }
                tempString  = tt;
            } else {
                tempString = tempName.replaceFirst(String.valueOf(tempName.charAt(0)), String.valueOf(tempName.charAt(0)).toUpperCase());
            }
            return tempString.trim();
        }

Upvotes: 0

Ranjan
Ranjan

Reputation: 91

Here we go for perfect first char capitalization of word

public static void main(String[] args) {
    String input ="my name is ranjan";
    String[] inputArr = input.split(" ");

    for(String word : inputArr) {
        System.out.println(word.substring(0, 1).toUpperCase()+word.substring(1,word.length()));
    }   
}

}

//Output : My Name Is Ranjan

Upvotes: 4

Bugs Happen
Bugs Happen

Reputation: 2268

Here is the Kotlin version of the same problem:

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()
}

Upvotes: 1

Alejandro Dirgan
Alejandro Dirgan

Reputation: 1

I made this little class that can be used to capitilize each word in a sentence. You can change the word separator in the string if this is not a space.

package com.ecnews.ecnews_v01.Helpers;

  public class Capitalize {

  String sentence;
  String separator = " ";

  public Capitalize(String sentence) {
    this.sentence = sentence;
  }

  public void setSeparator(String separator) {
    this.separator = separator;
  }

  public String getCapitalized() {
    StringBuilder capitalized = new StringBuilder("");
    for (String word : sentence.split(separator)) {
        capitalized.append(separator+Character.toUpperCase(word.charAt(0)) + word.substring(1));
    }
    return capitalized.toString().trim();
  }

}

Example:

String sourceName = new Capitalize("this is a test").getCapitalized();

sourceName will be "This Is A Test"

Upvotes: 0

Pirai Sudie
Pirai Sudie

Reputation: 172

this is another way i did

    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);

Upvotes: 0

Taladork
Taladork

Reputation: 41

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());
}

Upvotes: 4

Abhishek Bansal
Abhishek Bansal

Reputation: 5335

Here is RxJava solution to the problem

    String title = "this is a title";
    StringBuilder stringBuilder = new StringBuilder();
    Observable.fromArray(title.trim().split("\\s"))
        .map(word -> word.substring(0, 1).toUpperCase() + word.substring(1).toLowerCase())
        .toList()
        .map(wordList -> {
            for (String word : wordList) {
                stringBuilder.append(word).append(" ");
            }
            return stringBuilder.toString();
        })
        .subscribe(result -> System.out.println(result));

I don't yet like the for loop inside map though.

Upvotes: 0

Arun Raaj
Arun Raaj

Reputation: 1800

String text="hello";
StringBuffer sb=new StringBuffer();
char[] ch=text.toCharArray();
for(int i=0;i<ch.length;i++){
    if(i==0){
        sb.append(Character.toUpperCase(ch[i]));
    }
    else{
    sb.append(ch[i]);
    }
}


text=sb.toString();
System.out.println(text);
}

Upvotes: 0

Thaycacac
Thaycacac

Reputation: 1

    s.toLowerCase().trim();
    result += Character.toUpperCase(s.charAt(0));
    result += s.substring(1, s.indexOf(" ") + 1);
    s = s.substring(s.indexOf(" ") + 1);

    do {
        if (s.contains(" ")) {
            result += " ";
            result += Character.toUpperCase(s.charAt(0));
            result += s.substring(1, s.indexOf(" "));
            s = s.substring(s.indexOf(" ") + 1);
        } else {
            result += " ";
            result += Character.toUpperCase(s.charAt(0));
            result += s.substring(1);
            break;
        }
    } while (true);
    System.out.println(result);

Upvotes: 0

Tassadar
Tassadar

Reputation: 224

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();
}

Upvotes: 6

Tumi Mashabela
Tumi Mashabela

Reputation: 11

The most basic and easiest way to understand (I think):

import java.util.Scanner;

public class ToUpperCase {
    static Scanner kb = new Scanner(System.in);

    public static String capitalize(String str){
        /* Changes 1st letter of every word 
           in a string to upper case
         */
        String[] ss = str.split(" ");
        StringBuilder[] sb = new StringBuilder[ss.length];
        StringBuilder capped = new StringBuilder("");
        str = "";

        // Capitalise letters
        for (int i = 0; i < ss.length; i++){
            sb[i] = new StringBuilder(ss[i]); // Construct and assign
            str += Character.toUpperCase(ss[i].charAt(0)); // Only caps
            //======================================================//

            // Replace 1st letters with cap letters
            sb[i].setCharAt(0, str.charAt(i)); 
            capped.append(sb[i].toString() + " ");  // Formatting
        }
        return capped.toString();
    }

    public static void main(String[] args){
        System.out.println(capitalize(kb.nextLine()));
    }
}

Upvotes: 0

Amir Bareket
Amir Bareket

Reputation: 431

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

capitalizeStr = StringUtils.capitalize(str);

Upvotes: 10

Ameen Maheen
Ameen Maheen

Reputation: 2737

Try this:

 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();
    }

Upvotes: 1

Hylke1982
Hylke1982

Reputation: 221

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

Upvotes: 21

lwdthe1
lwdthe1

Reputation: 1280

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();
    }
}

Upvotes: 2

Phuoc Le
Phuoc Le

Reputation: 31

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;
}

Upvotes: 3

Sireesh Yarlagadda
Sireesh Yarlagadda

Reputation: 13716

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 "";
        }
    }
}

Upvotes: 2

jf Wastiaux
jf Wastiaux

Reputation: 21

This one works for the surname case...

With different types of separators, and it keeps the same separator:

  • jean-frederic --> Jean-Frederic

  • jean frederic --> Jean Frederic

The code works with the GWT client side.

public static String capitalize (String givenString) {
    String Separateur = " ,.-;";
    StringBuffer sb = new StringBuffer(); 
    boolean ToCap = true;
    for (int i = 0; i < givenString.length(); i++) {
        if (ToCap)              
            sb.append(Character.toUpperCase(givenString.charAt(i)));
        else
            sb.append(Character.toLowerCase(givenString.charAt(i)));

        if (Separateur.indexOf(givenString.charAt(i)) >=0) 
            ToCap = true;
        else
            ToCap = false;
    }          
    return sb.toString().trim();
}

Upvotes: 1

Daniel Wondyifraw
Daniel Wondyifraw

Reputation: 7713

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.

Upvotes: 1

foobar
foobar

Reputation: 2943

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);
}

Upvotes: 2

curd0
curd0

Reputation: 2482

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);

Upvotes: 3

Shristy
Shristy

Reputation: 1

public void capitaliseFirstLetterOfEachWord()
{
    String value="this will capitalise first character of each word of this string";
    String[] wordSplit=value.split(" ");
    StringBuilder sb=new StringBuilder();

    for (int i=0;i<wordSplit.length;i++){

        sb.append(wordSplit[i].substring(0,1).toUpperCase().
                concat(wordSplit[i].substring(1)).concat(" "));
    }
    System.out.println(sb);
}

Upvotes: 0

Simon
Simon

Reputation: 2986

I use wordUppercase(String s) from the Raindrop-Library. Because this is my library, here the single method:

 /**
  * Set set first letter from every word uppercase.
  *
  * @param s - The String wich you want to convert.
  * @return The string where is the first letter of every word uppercase.
  */
 public static String wordUppercase(String s){
   String[] words = s.split(" ");
   for (int i = 0; i < words.length; i++) words[i] = words[i].substring(0, 1).toUpperCase() + words[i].substring(1).toLowerCase();
   return String.join(" ", words);
 }

Hope it helps :)

Upvotes: 0

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