Java String toLowerCase()

In this tutorial, we will learn about the Java String toLowerCase() method with the help of examples.

The toLowerCase() method converts all characters in the string to lowercase characters.

Example

class Main {
  public static void main(String[] args) {
    String str1 = "JAVA PROGRAMMING";

    // convert to lower case letters
    System.out.println(str1.toLowerCase());

  }
}

// Output: java programming

Syntax of toLowerCase()

The syntax of the string toLowerCase() method is:

string.toLowerCase()

Here, string is an object of the String class.

toLowerCase() Parameters

The toLowerCase() method does not take any parameters.

toLowerCase() Return Value

returns a string with all upper case letters converted to lowercase letters

Example: Java toLowerCase()

class Main {
  public static void main(String[] args) {
    String str1 = "Learn Java";
    String str2 = "Java123";

    // convert to lowercase letters
    System.out.println(str1.toLowerCase());  // "learn java"
    System.out.println(str2.toLowerCase());  // "java123"

  }
}

As you can see from the above example, toLowerCase() converts all uppercase letters to lower case letters.

toLowerCase() With Locale Parameter

The toLowerCase() method can also take a locale as an argument. This allows you to convert characters in a string to lowercase using the given Locale (such as: Turkish, Lithuanian etc.) rules.

Its syntax is: