[Solved] Error: empty character literal
In this post, I will be sharing how to fix the error: empty character literal in Java. When we need to declare an empty char, usually, we use ‘ ‘ (empty single quotes) as a char. I have already shared 3 other ways to represent empty char in Java. As always, first, we will produce the error empty character literal before moving on to the solution.
[Fixed] Error: empty character literal
Example 1: Producing the error by printing the empty single quotes character
We can easily produce this error by printing the ‘ ‘ (empty single quotes) character as shown below:
public class EmptyCharacterLiteral public static void main(String args[]) char ch = ''; System.out.println("Print empty char" + ch); > >
Output:
/EmptyCharacterLiteral.java:3: error: empty character literal
char ch = ‘ ‘;
^
1 error
Explanation:
The cause of this compilation error is due to trying to print empty character in Java. As a result, we were getting an error: empty character literal.
Solution:
To overcome this compilation error, we can assign the char data type variable ch with the values Character.MIN_VALUE, or ‘\u0000‘, or ‘\0‘, as shown below:
public class EmptyCharacterLiteral public static void main(String args[]) // Assign null character to ch variable char ch = Character.MIN_VALUE; //OR //char ch = '\u0000'; //OR //char ch = '\0'; System.out.println("Print empty char" + ch); > >
Output:
Print empty char
Example 2: Producing the error by comparing the empty single quotes character
We can easily produce this error by comparing the ‘ ‘ (empty single quotes) character as shown below:
public class EmptyCharacterLiteral2 public static void main(String args[]) char ch = 'a'; // Comparing null character to ch variable if (ch == ('')) System.out.println("char is: " + ch); > >
Output:
/EmptyCharacterLiteral2.java:5: error: empty character literal
if (ch == (»))
^
1 error
Explanation:
The cause of this compilation error is due to trying to compare empty single quotes character with the char data type variable ch. As a result, we were getting error: empty character literal.
Solution:
To overcome this compilation error, we can replace the empty single quotes character with the values Character.MIN_VALUE, or ‘\u0000‘, or ‘\0‘, as shown below:
public class EmptyCharacterLiteral2 public static void main(String args[]) char ch = 'a'; // Comparing null character to ch variable if (ch == Character.MIN_VALUE)// OR (ch == '\u0000') OR (ch == '\0') System.out.println("char is: " + ch); > >
Output:
(No Output Printed)
That’s all for today. Please mention in the comments in case you are still facing the error: empty character literal in Java.
About The Author
Subham Mittal has worked in Oracle for 3 years.
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Represent Empty Char in Java
- Creating Empty Char in Java
- Creating Empty Char by Passing Null Char in Java
- Creating Empty Char by Using a Unicode Value in Java
- Creating Empty Char by Using MIN_VALUE Constant in Java
This tutorial introduces how to represent empty char in Java.
In Java, we can have an empty char[] array, but we cannot have an empty char because if we say char, then char represents a character at least, and an empty char does not make sense. An empty char value does not belong to any char, so Java gives a compile-time error.
To create an empty char, we either can assign it a null value \0 or default Unicode value \u0000 . The \u0000 is a default value for char used by the Java compiler at the time of object creation.
In Java, like other primitives, a char has to have a value. Let’s understand with some examples.
Creating Empty Char in Java
Let’s create an empty char in Java and try to compile the code. See in the below example, we created a single char variable ch and printed its value to check whether it has anything to print, and see it throws a compile-time error.
public class SimpleTesting public static void main(String[] args) char ch = ''; System.out.println(ch); > > Exception in thread "main" java.lang.Error: Unresolved compilation problem: Invalid character constant The above code example fails to compile because of an invalid character constant. It means Java does not recognize the empty char, but if we assign a char having a space, the code compiles successfully and prints an empty space to the console.
We must not confuse space char with empty char as both are different, and Java treats them differently. See the example below.
public class SimpleTesting public static void main(String[] args) char ch = ' '; System.out.println(ch); > > Creating Empty Char by Passing Null Char in Java
This is another solution that can be used to create empty char and can avoid code compilation failure. Here, we used \0 to create empty char and it works fine. See the example below.
public class SimpleTesting public static void main(String[] args) char ch = '\0'; System.out.println(ch); > > Creating Empty Char by Using a Unicode Value in Java
We can use \u0000 value to create an empty char in Java. The Java compiler uses this value to set as char initial default value. It represents null that shows empty char. See the example below.
public class SimpleTesting public static void main(String[] args) char ch1 = '\u0000'; System.out.println(ch1); > > Creating Empty Char by Using MIN_VALUE Constant in Java
Java Character class provides a MIN_VALUE constant that represents the minimum value for a character instance. In Java, the minimum value is a \u0000 that can be obtained using the MIN_VALUE constant of the Character class and can be assigned to any char variable to create an empty char. See the example below.
public class SimpleTesting public static void main(String[] args) char ch = Character.MIN_VALUE; System.out.println(ch); > > If you are working with the Character class, you can directly use null literal to create an empty char instance in Java. As the Character class is derived from the Object class, we can assign null as an instance. See the example below.
public class SimpleTesting public static void main(String[] args) Character ch = null; System.out.println(ch); > > Related Article — Java Char
How to Represent Empty char in Java
“char” is a primitive data type belonging to the Character class used to declare char type variables represented by the char Java keyword. Java allows you to use an empty char[] array, but not an empty char; as a char must represent at least one character, the null or an empty char makes no sense.
This tutorial will show you how to represent an empty string in Java. So, let’s start!
How to Represent Empty char in Java?
To represent an empty char in Java, use the following methods:
Let’s understand how these methods help in the specified purpose.
Method 1: Represent Empty char in Java Using Empty Single Quotes
When we come across such scenarios where it is required to declare an empty “char”, the first thing that comes to mind is to assign single quotes (”) as a “char”. A compile-time error is generated by Java as a result of this method because an empty value of char does not belong to any character.
Example 1
We will assign a single quote (”) to a character type variable named “ch”:
It will show an error “invalid character constant”:
For solving the above problem, we will enter a space between single quotes (‘ ‘) as a character. The space will act as a character, and Java will consider it as a null or empty char:
We will print the value of the char variable “ch” using print statement:
The output signifies that the char variable “ch” is empty:
Method 2: Represent Empty char in Java Using Null Character
You can also represent a char as an empty character using a “Null Character” (\0), where the character “\0” denotes a null value.
Let’s see an example of how \0 acts as an empty character.
Example
Here, we will assign a null character to a char variable “ch”:
Then, print the out the character value with the help of the “System.out.println()” method:
The output shows that the char “ch” is empty:
Method 3: Represent Empty char in Java Using Unicode Value (\u0000)
Another method to represent an empty char is utilizing the Unicode value “\u0000”. The given Unicode represents a null value.
Let’s move towards an example for better understanding.
Example
In this example, we will allocate a Unicode value “\u0000” to a “ch” variable:
Then, we will print the created empty char on the console:
The output indicates that char is null:
Method 4: Represent Empty char in Java Using MIN_VALUE Constant
“MIN_VALUE Constant” represents a character instance’s minimum value. In Java, the minimum value is an “u0000”, which can be retrieved by utilizing the MIN_ VALUE constant that belongs to the Character class, and passed to any char type variable for creating an empty character.
Example
We will now assign the constant of the Character class named “MIN_VALUE” constant to a char variable “ch”:
Then, print the variable “ch” to see either it is empty or not:
The output indicates that the “ch” is empty:
We gathered all the methods to represent an empty char in Java.
Conclusion
To represent empty char in Java, you can use different methods such as empty single quotes, null character (\0), Unicode value (\u0000), MIN_VALUE Constant of the Character class. In empty single quotes, if you do not enter space between quotes, it throws an error because an empty char value does not belong to any character. To resolve this issue, enter a space between single quotes. This tutorial explained the methods for representing empty char in Java with detailed examples.
About the author
Farah Batool
I completed my master’s degree in computer science. I am an academic researcher and love to learn and write about new technologies. I am passionate about writing and sharing my experience with the world.
null character java
In this tutorial, I will be sharing about the null character in java. char keyword represents a primitive data type. First, we will look into how to represent empty char in Java.
The length of the null character in Java is not 0 but 1 as shown below:
String str = Character.toString('\0');
System.out.println(str.length()); // Output: "1"
How to represent a Null or Empty Character in Java
There are 3 ways through which we can represent the null or empty character in Java.
1. Using Character.MIN_VALUE
2. Using ‘\u0000’
3. Using ‘\0’
1. Using Character.MIN_VALUE
Below we have assigned the smallest value of char data type i.e. Character.MIN_VALUE to variable ch.
public class EmptyCharacterExample public static void main(String args[]) // Assign null character to ch variable char ch = Character.MIN_VALUE; String givenString = "Alive is Awesome"; // Replacing 'A' in the givenString with null character String result = givenString.replace('A',ch); // Printing the result string System.out.println("Replace givenString with null char: " + result); > >
Output:
Replace givenString with null char: live is wesome
2. Using ‘\u0000’
We will assign char variable ch with ‘\u0000’. ‘\u0000’ is the lowest range of the Unicode system used by Java.
public class EmptyCharacterExample2 public static void main(String args[]) // Assign null character to ch variable char ch = '\u0000'; String givenString = "Be in present"; // Replacing 'e' in the givenString with null character String result = givenString.replace('e',ch); // Printing the result string System.out.println("Replace givenString with null char: " + result); > >
Output:
Replace givenString with null char: B in pr s nt
3. Using ‘\0’
We will assign char variable ch with ‘\0’ special character. ‘\0’ represents null.
public class EmptyCharacterExample3 public static void main(String args[]) // Assign null character to ch variable char ch = '\0'; String givenString = "Love Yourself"; // Replacing 'o' in the givenString with null character String result = givenString.replace('o',ch); // Printing the result string System.out.println("Replace givenString with null char: " + result); > >
Output:
Replace givenString with null char: L ve Y urself
That’s all for today. Please mention in the comments in case you have any questions related to the null character in java.
About The Author
Subham Mittal has worked in Oracle for 3 years.
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