A null character is a special type of character, called a control character, with all its bits set to zero. It is often used in computer programming languages to mark the end of a string. In practical applications, such as database and spreadsheet programs, null characters are used as filler spaces.
In most character encoding sets, such as UTF-8 and ASCII, the null character is the first character in the set. When represented in binary, it appears as all 0s, or 00000000.
A null character in computer source code is often represented by the escape character sequence \0, and is used by programmers to manually set the end of a string. For example, a piece of programming code that stores the text string "Help" will store the following individual characters:
"H" "e" "l" "p" "\0"
The null character, \0, marks the end of the string. Since the null character is a single byte, it is more computationally efficient than using several bytes to set a length when the string is created.