How to capitalize the first letter of a String in Java?

Question

I am using Java to get a String input from the user. I am trying to make the first letter of this input capitalized.

I tried this:

String name;

BufferedReader br = new InputStreamReader(System.in);

String s1 = name.charAt(0).toUppercase());

System.out.println(s1 + name.substring(1));

which led to these compiler errors:

• Type mismatch: cannot convert from InputStreamReader to BufferedReader

• Cannot invoke toUppercase() on the primitive type char

Answer 1

String str = "java";
String cap = str.substring(0, 1).toUpperCase() + str.substring(1);
// cap = "Java"

With your example:

public static void main(String[] args) throws IOException {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    // Actually use the Reader
    String name = br.readLine();
    // Don't mistake String object with a Character object
    String s1 = name.substring(0, 1).toUpperCase();
    String nameCapitalized = s1 + name.substring(1);
    System.out.println(nameCapitalized);
}

Answer 2

StringUtils.capitalize(..) from commons-lang

Answer 3

The shorter/faster version code to capitalize the first letter of a String is:

String name  = "stackoverflow"; 
name = name.substring(0,1).toUpperCase() + name.substring(1).toLowerCase();

the value of name is "Stackoverflow"

Answer 4

Use Apache's common library. Free your brain from these stuffs and avoid Null Pointer & Index Out Of Bound Exceptions

Step 1:

Import apache's common lang library by putting this in build.gradle dependencies

compile 'org.apache.commons:commons-lang3:3.6'

Step 2:

If you are sure that your string is all lower case, or all you need is to initialize the first letter, directly call

StringUtils.capitalize(yourString);

If you want to make sure that only the first letter is capitalized, like doing this for an enum, call toLowerCase() first and keep in mind that it will throw NullPointerException if the input string is null.

StringUtils.capitalize(YourEnum.STUFF.name().toLowerCase());
StringUtils.capitalize(yourString.toLowerCase());

Here are more samples provided by apache. it's exception free

StringUtils.capitalize(null)  = null
StringUtils.capitalize("")    = ""
StringUtils.capitalize("cat") = "Cat"
StringUtils.capitalize("cAt") = "CAt"
StringUtils.capitalize("'cat'") = "'cat'"

Note:

WordUtils is also included in this library, but is deprecated. Please do not use that.

Answer 5

Java:

simply a helper method for capitalizing every string.

public static String capitalize(String str)
{
    if(str == null) return str;
    return str.substring(0, 1).toUpperCase() + str.substring(1);
}

After that simply call str = capitalize(str)

---

Kotlin:

str.capitalize()

Answer 6

What you want to do is probably this:

s1 = name.substring(0, 1).toUpperCase() + name.substring(1);

(converts first char to uppercase and adds the remainder of the original string)

Also, you create an input stream reader, but never read any line. Thus name will always be null.

This should work:

BufferedReader br = new InputstreamReader(System.in);
String name = br.readLine();
String s1 = name.substring(0, 1).toUpperCase() + name.substring(1);

Answer 7

if you use SPRING:

import static org.springframework.util.StringUtils.capitalize;
...


    return capitalize(name);

IMPLEMENTATION: org/springframework/util/StringUtils.java#L535-L555

REF: javadoc-api/org/springframework/util/StringUtils.html#capitalize

---

NOTE: If you already have Apache Common Lang dependency, then consider using their StringUtils.capitalize as other answers suggest.

Answer 8

WordUtils.capitalize(java.lang.String) from Apache Commons.

Answer 9

Below solution will work.

String A = "stackOverflow";
String ACaps = A.toUpperCase().charAt(0)+A.substring(1,A.length());
//Will print StackOverflow

You can't use toUpperCase() on primitive char , but you can make entire String to Uppercase first then take the first char, then to append to the substring as shown above.

Answer 10

Use WordUtils.capitalize(str).

Answer 11

String str1 = "hello";
str1.substring(0, 1).toUpperCase()+str1.substring(1);

Answer 12

Set the string to lower case, then set the first Letter to upper like this:

    userName = userName.toLowerCase();

then to capitalise the first letter:

    userName = userName.substring(0, 1).toUpperCase() + userName.substring(1).toLowerCase();

substring is just getting a piece of a larger string, then we are combining them back together.

Answer 13

Shortest too:

String message = "my message";    
message = Character.toUpperCase(message.charAt(0)) + message.substring(1);
System.out.println(message)    // Will output: My message

Worked for me.

Answer 14

Use this utility method to get all first letter in capital.

String captializeAllFirstLetter(String name) 
{
    char[] array = name.toCharArray();
    array[0] = Character.toUpperCase(array[0]);

    for (int i = 1; i < array.length; i++) {
        if (Character.isWhitespace(array[i - 1])) {
            array[i] = Character.toUpperCase(array[i]);
        }
    }

    return new String(array);
}

Answer 15

IT WILL WORK 101%

public class UpperCase {

    public static void main(String [] args) {

        String name;

        System.out.print("INPUT: ");
        Scanner scan = new Scanner(System.in);
        name  = scan.next();

        String upperCase = name.substring(0, 1).toUpperCase() + name.substring(1);
        System.out.println("OUTPUT: " + upperCase); 

    }

}

Answer 16

In Android Studio

Add this dependency to your build.gradle (Module: app)

dependencies {
    ...
    compile 'org.apache.commons:commons-lang3:3.1'
    ...
}

Now you can use

String string = "STRING WITH ALL CAPPS AND SPACES";

string = string.toLowerCase(); // Make all lowercase if you have caps

someTextView.setText(WordUtils.capitalize(string));

Answer 17

What about WordUtils.capitalizeFully()?

import org.apache.commons.lang3.text.WordUtils;

public class Main {

    public static void main(String[] args) {

        final String str1 = "HELLO WORLD";
        System.out.println(capitalizeFirstLetter(str1)); // output: Hello World

        final String str2 = "Hello WORLD";
        System.out.println(capitalizeFirstLetter(str2)); // output: Hello World

        final String str3 = "hello world";
        System.out.println(capitalizeFirstLetter(str3)); // output: Hello World

        final String str4 = "heLLo wORld";
        System.out.println(capitalizeFirstLetter(str4)); // output: Hello World
    }

    private static String capitalizeFirstLetter(String str) {
        return WordUtils.capitalizeFully(str);
    }
}

Answer 18

You can use substring() to do this.

But there are two different cases:

Case 1

If the String you are capitalizing is meant to be human-readable, you should also specify the default locale:

String firstLetterCapitalized = 
    myString.substring(0, 1).toUpperCase(Locale.getDefault()) + myString.substring(1);

Case 2

If the String you are capitalizing is meant to be machine-readable, avoid using Locale.getDefault() because the string that is returned will be inconsistent across different regions, and in this case always specify the same locale (for example, toUpperCase(Locale.ENGLISH)). This will ensure that the strings you are using for internal processing are consistent, which will help you avoid difficult-to-find bugs.

Note: You do not have to specify Locale.getDefault() for toLowerCase(), as this is done automatically.

Answer 19

Here is my detailed article on the topic for all possible options Capitalize First Letter of String in Android

Method to Capitalize First Letter of String in Java

public static String capitalizeString(String str) {
        String retStr = str;
        try { // We can face index out of bound exception if the string is null
            retStr = str.substring(0, 1).toUpperCase() + str.substring(1);
        }catch (Exception e){}
        return retStr;
}

Method to Capitalize First Letter of String in KOTLIN

fun capitalizeString(str: String): String {
        var retStr = str
        try { // We can face index out of bound exception if the string is null
            retStr = str.substring(0, 1).toUpperCase() + str.substring(1)
        } catch (e: Exception) {
        }
        return retStr
}

Answer 20

You can also try this:

 String s1 = br.readLine();
 char[] chars = s1.toCharArray();
 chars[0] = Character.toUpperCase(chars[0]);
 s1= new String(chars);
 System.out.println(s1);

This is better(optimized) than with using substring. (but not to worry on small string)

Answer 21

try this one

What this method does is that, Consider the word "hello world" this method turn it into "Hello World" capitalize the beginning of each word .

 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();

    }

Answer 22

Current answers are either incorrect or over-complicate this simple task. After doing some research, here are two approaches I come up with:

1. String's substring() Method

public static String capitalize(String str) {
    if(str== null || str.isEmpty()) {
        return str;
    }

    return str.substring(0, 1).toUpperCase() + str.substring(1);
}

Examples:

System.out.println(capitalize("java")); // Java
System.out.println(capitalize("beTa")); // BeTa
System.out.println(capitalize(null)); // null

2. Apache Commons Lang

The Apache Commons Lang library provides StringUtils the class for this purpose:

System.out.println(StringUtils.capitalize("apache commons")); // Apache commons
System.out.println(StringUtils.capitalize("heLLO")); // HeLLO
System.out.println(StringUtils.uncapitalize(null)); // null

Don't forget to add the following dependency to your pom.xml file:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.9</version>
</dependency>

Answer 23

Simple solution! doesn't require any external library, it can handle empty or one letter string.

private String capitalizeFirstLetter(@NonNull  String str){
        return str.length() == 0 ? str
                : str.length() == 1 ? str.toUpperCase()
                : str.substring(0, 1).toUpperCase() + str.substring(1).toLowerCase();
}

Answer 24

This is just to show you, that you were not that wrong.

BufferedReader br = new InputstreamReader(System.in);
// Assuming name is not blank
String name = br.readLine(); 

//No more error telling that you cant convert char to string
String s1 = (""+name.charAt(0)).toUppercase());
// Or, as Carlos prefers. See the comments to this post.
String s1 = Character.toString(name.charAt(0)).toUppercase());

System.out.println(s1+name.substring(1));

Note: This is not at all the best way to do it. This is just to show the OP that it can be done using charAt() as well. ;)

Answer 25

This will work

char[] array = value.toCharArray();

array[0] = Character.toUpperCase(array[0]);

String result = new String(array);

Answer 26

You can use the following code:

public static void main(String[] args) {

    capitalizeFirstLetter("java");
    capitalizeFirstLetter("java developer");
}

public static void capitalizeFirstLetter(String text) {

    StringBuilder str = new StringBuilder();

    String[] tokens = text.split("\\s");// Can be space,comma or hyphen

    for (String token : tokens) {
        str.append(Character.toUpperCase(token.charAt(0))).append(token.substring(1)).append(" ");
    }
    str.toString().trim(); // Trim trailing space

    System.out.println(str);

}

Answer 27

Given answers is for capitalize the first letter of one word only. use following code to capitalize a whole string.

public static void main(String[] args) {
    String str = "this is a random string";
    StringBuilder capitalizedString = new StringBuilder();
    String[] splited = str.trim().split("\\s+");

    for (String string : splited) {         
        String s1 = string.substring(0, 1).toUpperCase();
        String nameCapitalized = s1 + string.substring(1);

        capitalizedString.append(nameCapitalized);
        capitalizedString.append(" ");
    }
    System.out.println(capitalizedString.toString().trim());
}

output : This Is A Random String

Answer 28

If Input is UpperCase ,then Use following :

str.substring(0, 1).toUpperCase() + str.substring(1).toLowerCase();

If Input is LowerCase ,then Use following :

str.substring(0, 1).toUpperCase() + str.substring(1);

Answer 29

Using commons.lang.StringUtils the best answer is:

public static String capitalize(String str) {  
    int strLen;  
    return str != null && (strLen = str.length()) != 0 ? (new StringBuffer(strLen)).append(Character.toTitleCase(str.charAt(0))).append(str.substring(1)).toString() : str;  
}

I find it brilliant since it wraps the string with a StringBuffer. You can manipulate the StringBuffer as you wish and though using the same instance.

Answer 30

TO get First letter capital and other wants to small you can use below code. I have done through substring function.

String currentGender="mAlE";
    currentGender=currentGender.substring(0,1).toUpperCase()+currentGender.substring(1).toLowerCase();

Here substring(0,1).toUpperCase() convert first letter capital and substring(1).toLowercase() convert all remaining letter into a small case.

OUTPUT:

Male