# Capitalize the first letter of a string in Java

By Atta Ur Rehman Shah (https://attacomsian.com/about). Published Sep 14, 2019, updated Sep 30, 2022. Topics: Java.
Canonical URL: https://attacomsian.com/blog/capitalize-first-letter-of-string-java

> Learn how to capitalize the first letter of a string in Java by using the String's substring() method and Apache Commons Lang library. 

In this quick tutorial, you will learn how to **capitalize the first letter of a string** in Java. Unfortunately, the `String` class does not provide any method to capitalize strings. However, there are methods available to change the case of the string (uppercase, lowercase, etc.).

## Using `String.substring()` Method

The simplest way to capitalize the first letter of a string in Java is by using the `String.substring()` method:

```java
String str = "hello world!";

// capitalize first letter
String output = str.substring(0, 1).toUpperCase() + str.substring(1);

// print the string
System.out.println(output);
// Hello world!
```

The above example transforms the first letter of string `str` to uppercase and leaves the rest of the string the same. If the string is `null` or empty, the above code throws an exception. 

However, we can write a functional `capitalize()` that makes sure the string has at least one character before using the `substring()` method:

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

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

Now just call the `capitalize()` method whenever you want to make the first letter of a string uppercase:

```java
System.out.println(capitalize("hello world!")); // Hello world!
System.out.println(capitalize("heLLo")); // HeLLo
System.out.println(capitalize(null)); // null
```

Notice the 2nd line of the above code snippet, only the first letter is capitalized. If you want to ensure only the first letter is in uppercase and the remaining string is lowered case, you can do the following:

```java
str.substring(0, 1).toUpperCase() + str.substring(1).toLowerCase()
```

## Using Apache Commons Lang

The [Apache Commons Lang](https://commons.apache.org/proper/commons-lang/) library is another way to capitalize the first letter of a string in Java. If you are using Gradle, add the following dependency to your `build.gradle` file:

```groovy
implementation 'org.apache.commons:commons-lang3:3.9'
```
 
For Maven, add the dependency below to your `pom.xml` file:

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

The `StringUtils` class from Commons Lang provides the `capitalize()` method to change the first letter to uppercase:

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

Apache Commons Lang offers many extra methods that are not included in standard Java libraries (`java.lang` package). It includes String manipulation methods, basic numerical methods, object reflection, concurrency, creation and serialization, and System properties.

## Conclusion

In this article, we looked at different ways to capitalize the first letter of a string in Java. The simple approach is to use the `String` class's `substring()` method. However, if you are already using Apache Commons Lang in your project, just use the `StringUtils` class to capitalize the first letter of a string.

Since string capitalization is a common task in all programming languages, I have also written a tutorial to do the same in JavaScript. Take a look at [this guide](https://attacomsian.com/blog/string-capitalize-javascript).

**Read Next:** [Capitalize the first letter of each word in a string using Java](https://attacomsian.com/blog/capitalize-first-letter-of-each-word-in-string-java)