How to represent empty char in Java Character class


I want to represent an empty character in Java as "" in String...

Like that char ch = an empty character;

Actually I want to replace a character without leaving space.

I think it might be sufficient to understand what this means: no character not even space.

8/25/2019 10:49:58 PM

char means exactly one character. You can't assign zero characters to this type.

That means that there is no char value for which String.replace(char, char) would return a string with a diffrent length.


As Character is a class deriving from Object, you can assign null as "instance":

Character myChar = null;

Problem solved ;)


An empty String is a wrapper on a char[] with no elements. You can have an empty char[]. But you cannot have an "empty" char. Like other primitives, a char has to have a value.

You say you want to "replace a character without leaving a space".

If you are dealing with a char[], then you would create a new char[] with that element removed.

If you are dealing with a String, then you would create a new String (String is immutable) with the character removed.

Here are some samples of how you could remove a char:

public static void main(String[] args) throws Exception {

    String s = "abcdefg";
    int index = s.indexOf('d');

    // delete a char from a char[]
    char[] array = s.toCharArray();
    char[] tmp = new char[array.length-1];
    System.arraycopy(array, 0, tmp, 0, index);
    System.arraycopy(array, index+1, tmp, index, tmp.length-index);
    System.err.println(new String(tmp));

    // delete a char from a String using replace
    String s1 = s.replace("d", "");

    // delete a char from a String using StringBuilder
    StringBuilder sb = new StringBuilder(s);
    s1 = sb.toString();


As chars can be represented as Integers (ASCII-Codes), you can simply write:

char c = 0;

The 0 in ASCII-Code is null.


If you want to replace a character in a String without leaving any empty space then you can achieve this by using StringBuilder. String is immutable object in java,you can not modify it.

String str = "Hello";
StringBuilder sb = new StringBuilder(str);
sb.deleteCharAt(1); // to replace e character

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