Java Character isLowerCase() Example

Java Character API comes with many methods to check the case of a letter – lowercase or uppercase. After checking, the character can be converted from lowercase to uppercase or uppercase to lowercase as per the need of the logic.

Following is the method signature as defined in java.lang.Character class.

• public static boolean isLowerCase(char ch): Tests if the specified character ch is a lowercase character and the result of validation is returned as a boolean value.

Following Java Character isLowerCase() Example illustrates.

public class CharacterFunctionDemo
{
  public static void main(String args[])
  {
 
    char ch1 = 'A';
    char ch2 = 'a';

    boolean b1 = Character.isLowerCase(ch1);
    boolean b2 = Character.isLowerCase(ch2);

    System.out.println(ch1 + " character is lowercase letter: " + b1);     
    System.out.println(ch2 + " character is lowercase letter: " + b2);   

                  // isLowerCase() can be used in control structures like this
    if(Character.isLowerCase('b') ==  Character.isLowerCase('k'))
    {
      System.out.println("\nBoth b and k are lowercase letters");
    }
                 // after checking, change the case
    if(! Character.isLowerCase('B'))
    {
      System.out.println("\nB is converted to lowercase letter: " + Character.toLowerCase('B'));
    }
  }
}

Character.toLowerCase('B')

The static method toLowerCase(char ch) converts uppercase letter to lowercase letter. Check for the usage of isUpperCase().