- Must be surrounded by single quotes (')
- May include any single printable character (e.g. 'a')
- May include any single non-printable character using escape sequences, also called diagraphs (e.g. '\0' for NUL)
Examples of Valid Character Literals
|'a'||'T'||'\n'||'5'||'@'||' ' (space)|
Examples of Invalid Character Literals
Because the single quote (') is used to delimit character literals, the single quote cannot by itself be a character literal. It must be specified using an escape sequence: '\''
Although escape sequences look like two characters, the backslash (\) is treated specially in character and string literals. It signals that the character that follows is special. It either represents a non-printable character, as in the case of '\0' for NUL, or a character that cannot be used on its own in a character literal, such as the single quote or backslash themselves, which are represented as '\'' and '\\' respectively.