What is StringUtils.lowerCase in Java?

Overview

lowerCase() is a staticthe methods in Java that can be called without creating an object of the class. method of StringUtils which is used to convert a string to lowercase. This method optionally takes a locale. If the locale is not specified, then the default locale of the system is taken. The method returns null if the input string is null.

How to import StringUtils

The definition of StringUtils can be found in the Apache Commons Lang package, which we can add to the Maven project by adding the following dependency to the pom.xml file:


<dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
</dependency>

For other versions of the commons-lang package, refer to the Maven Repository.

You can import the StringUtils class as follows:


import org.apache.commons.lang3.StringUtils;

Syntax


public static String lowerCase(final String str, final Locale locale)

Parameters

  • final String str: The string to convert to lowercase.
  • final Locale locale: The locale that defines the case transformation rules.

Return value

This method returns a lowercase string.

Overloaded Methods

public static String lowerCase(final String str)

Code

import org.apache.commons.lang3.StringUtils;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
String s = "HellO-EDUcative";
System.out.printf("The output of StringUtils.lowerCase() for the string - '%s' is %s", s, StringUtils.lowerCase(s, Locale.ENGLISH));
System.out.println();
s = "";
System.out.printf("The output of StringUtils.lowerCase() for the string - '%s' is %s", s, StringUtils.lowerCase(s, Locale.ENGLISH));
System.out.println();
s = null;
System.out.printf("The output of StringUtils.lowerCase() for the string - '%s' is %s", s, StringUtils.lowerCase(s, Locale.ENGLISH));
System.out.println();
}
}

Example 1

  • string = "HellO-EDUcative"
  • locale = english

The method returns hello-educative when the string is converted to lowercase.

Example 2

  • string = ""
  • locale = english

The method returns `` as the input string is empty.

Example 3

  • string = null
  • locale = english

The method returns null as the input string is null.

Output

The output of the code will be as follows:


The output of StringUtils.lowerCase() for the string - 'HellO-EDUcative' is hello-educative
The output of StringUtils.lowerCase() for the string - '' is 
The output of StringUtils.lowerCase() for the string - 'null' is null
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