String toLowerCase() Method in Java

What is the toLowerCase() Method?

Java facilitates with a built-in method to convert the String contents to lower case using the toLowerCase() method.

Method Header


public String toLowerCase()

Method Arguments

Not any. [It operates perfectly fine without arguments. However, it does take an area-based parameter for punctuation rules called Locale, which is out of the scope of this post.]

Return Type

A String in lower case.

Example 1

Let’s have a look at an example to understand this better.


public class ToLowerCase {
    public static void main(String[] args) {
        String myName = "Lubaina Khan";
        System.out.println("How do you spell your name? " + myName);
        // using toLowerCase() method
        System.out.println("May I have a lower case version? " + myName.toLowerCase());
    }
}

Output

How do you spell your name? Lubaina Khan May I have a lower case version? lubaina khan

Example 2


public class ToLowerCase {

	public static void main(String[] args) {

		String date = java.util.Calendar.getInstance().getTime().toString();
		System.out.println("System Date : " + date);
		// using toLowerCase() method
		System.out.println("[lower case] : " + date.toLowerCase() + "\n");

		String paragraph = "This constantly evolving world still needs Java.";
		System.out.println("Original Paragraph: " + paragraph);
		// using toLowerCase() method
		System.out.println("[lower case] : " + paragraph.toLowerCase() + "\n");

		String punctuationPara = "Would you like to have some tea, Miss Peterson?";
		System.out.println("Punctuation Paragraph: " + punctuationPara);
		// using toLowerCase() method
		System.out.println("[lower case] : " + punctuationPara.toLowerCase() + "\n");
	}
}

Output

System Date : Sat Jul 24 08:36:01 PKT 2021 [lower case] : sat jul 24 08:36:01 pkt 2021 Original Paragraph: This constantly evolving world still needs Java. [lower case] : this constantly evolving world still needs java. Punctuation Paragraph: Would you like to have some tea, Miss Peterson? [lower case] : would you like to have some tea, miss peterson?

Conclusion

That was a quick demonstration of using the String toLowerCase() method in Java. We encourage you to learn by practice. Feel free to replug in case of any ambiguity.