Java - Character isLetter() method

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The Java Character isLetter() method determines if the specified character is a letter.

A character is considered to be a letter if its general category type, the return value obtained by the Character.getType() method, is any of the following −

• UPPERCASE_LETTER

• LOWERCASE_LETTER

• TITLECASE_LETTER

• MODIFIER_LETTER

• OTHER_LETTER

Not all letters have case; many characters are letters but are neither uppercase nor lowercase nor titlecase.

Syntax

Following is the syntax for Java Character isLetter() method

public static boolean isLetter(char ch)
(or)
public static boolean isLetter(int codePoint)

Parameters

• ch − the character to be tested

• codePoint − the Unicode code point to be tested

Return Value

This method returns true if the character argument is a letter, otherwise false.

Checking If a char/codepoint is a letter Example

The following example shows the usage of Java Character isLetter(char ch) method. In this example, we've created a char variable and int variables and assigned them some values. Now using isLetter() method, we've checked and printed the status of these variables as being letter or not.

package com.tutorialspoint;

public class CharacterDemo {
   public static void main(String[] args) {

      // create 2 primitives ch1 (char), cp1 (int)
      char ch1;
      int cp1;

      // assign values to ch1, cp1
      ch1 = 'A';
      cp1 = 0x0045;

      // create 2 boolean primitives b1, b2
      boolean b1, b2;

      // check if ch1, cp1 are letter or not and assign results to b1, b2
      b1 = Character.isLetter(ch1);
      b2 = Character.isLetter(cp1);
      String str1 = ch1 + " is a letter is " + b1;
      String str2 = (char)cp1 + " is a letter is " + b2;

      // print b1, b2 values
      System.out.println( str1 );
      System.out.println( str2 );
   }
}

Output

Let us compile and run the above program, this will produce the following result −

A is a letter is true
E is a letter is true

Checking If a codepoint is a letter Example

The following example shows the usage of Java Character isLetter(int codepoint) method. In this example, we've created a int variable and assigned it some value. Now using isLetter() method, we've checked and printed the status of this variable as being letter or not.

The following example shows the usage of Java Character isLetter(int codePoint) method.

package com.tutorialspoint;

public class isLetterDemo{
   public static void main(String []args){
      int cp = 0x0012;
      boolean b;        
      b = Character.isLetter(cp);        
      System.out.println(b);
   }
}

Output

Let us compile and run the above program, this will produce the following result −

false

Checking If a Character/codepoint is a letter Example

Another example to check whether the input character is a letter or not using the method is given below

package com.tutorialspoint;

public class CharacterDemo {
   public static void main(String[] args) {

      // create 2 primitives ch1 (char), cp1 (int) and assign titlecase letters
      Character ch1 = new Character('ĵ');
      int cp1 = 0x01C5;

      // create 2 boolean primitives b1, b2
      boolean b1, b2;

      // check if ch1, cp1 are letter or not and assign results to b1, b2
      b1 = Character.isLetter(ch1);
      b2 = Character.isLetter(cp1);

      // print b1, b2 values
      System.out.println(ch1 + " is a letter is " + b1);
      System.out.println("cp1 character is a letter: " + b2);
   }
}

Output

If we compile and run the program, we get the following output −

ĵ is a letter is true
cp1 character is a letter: true

Checking If a Modified letter is a letter Example

Let us now look at an example that determines whether the modifier letters are letters using this method.

package com.tutorialspoint;

public class Main {
   public static void main(String[] args) {

      // create 2 primitives ch1 (char), cp1 (int)
      Character ch1 = new Character('ʲ');
      int cp1 = 0x02C0;

      // create 2 boolean primitives b1, b2
      boolean b1, b2;

      // check if ch1, cp1 are letter or not and assign results to b1, b2
      b1 = Character.isLetter(ch1);
      b2 = Character.isLetter(cp1);

      // print b1, b2 values
      System.out.println(ch1 + " is a letter is " + b1);
      System.out.println("cp1 character is a letter: " + b2);
   }
}

Output

The output is displayed after compiling and running the above program as follows −

ʲ is a letter is true
cp1 character is a letter: true