Empty string

Formally, a string is a finite, ordered sequence of characters such as letters, digits or spaces.

Even a string of length zero can require memory to store it, depending on the format being used.

Some languages treat some or all of the following in similar ways: empty strings, null references, the integer 0, the floating point number 0, the Boolean value false, the ASCII character NUL, or other such values.

Different functions, methods, macros, or idioms exist for checking if a string is empty in different languages.

Since the empty string does not have a standard visual representation outside of formal language theory, the number zero is traditionally represented by a single decimal digit 0 instead.