Java – Capitalize the first letter of a String

In this short tutorial, you will get an idea of how to capitalize the first letter of a string. In Java, it can be possible in many ways like using core Java programming or using any third-party library e.g. Apache Commons Lang 3.

Java - Capitalize the first letter of a String

Similar Post: Capitalize the first letter of each word in a String using Java

1. Java 8 Lambda Expression

Java 8 introduced the Supplier<T> functional interface to implement the lambda expression in Java.

final String cityName = "new Delhi";
Supplier<String> str = () -> cityName.substring(0, 1).toUpperCase() + cityName.substring(1);

System.out.println(str.get()); // New Delhi

2. Core Java Programming

With Core Java programming, it will just increase the number of lines in your codebase, and the logic will remain the same as Java 8 Lambda Expression.
package org.websparrow;

import java.util.function.Supplier;

public class CapitalizeFirstLetter {

    public static void main(String[] args) {

        final String cityName1 = capitalizeFirstLetter("varanasi");
        System.out.println(cityName1); // Varanasi

        final String cityName2 = capitalizeFirstLetter("VARANASI");
        System.out.println(cityName2); // VARANASI

        final String cityName3 = capitalizeFirstLetter("$varanasi");
        System.out.println(cityName3); // $varanasi


    public static String capitalizeFirstLetter(final String str) {

        if (null == str || str.trim().equals("")) {
            throw new RuntimeException("String is not valid");
        return str.substring(0, 1).toUpperCase().concat(str.substring(1));



3. Apache Commons Lang 3

With Apache Commons Lang 3 library, you can use its StringUtils.capitalize(String str) API to capitalize the first letter of a string. You can grab the Apache commons-lang3 by adding the below dependency to your pom.xml file.

// Apache Commons Lang 3, StringUtils
final String name1 = StringUtils.capitalize("atul");
System.out.println(name1); // Atul

final String name2 = StringUtils.capitalize("atul rai");
System.out.println(name2); // Atul rai

final String name3 = StringUtils.capitalize("ATUL RAI");
System.out.println(name3); // ATUL RAI

final String name4 = StringUtils.capitalize("@atul rai");
System.out.println(name4); // @atul rai

In Apache commons-lang3 library, there is another WordUtils.capitalize(String str) API that capitalizes the first letter of each word of a string, but it is deprecated from the 3.6.0 version.

// Apache Commons Lang 3, WordUtils
final String foo = WordUtils.capitalize("cow");
System.out.println(foo); // Cow

final String boo = WordUtils.capitalize("i'm a holy cow.");
System.out.println(boo); // I'm A Holy Cow.


  1. Interface Supplier<T>- Java 8
  2. StringUtils- Apache Commons Lang 3
  3. WordUtils- Apache Commons Lang 3
  4. How to capitalize the first letter of a String in PHP

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Atul Rai
I love sharing my experiments and ideas with everyone by writing articles on the latest technological trends. Read all published posts by Atul Rai.