About Character Literals
A character literal is any string of characters enclosed in quotation marks as shown in the following example:
‘This is a character string.’
“This is a character string, too.”
For convenience, you can enter character literals without the delimiting quotation marks; however, quotation marks are required in some situations. The rules for using quotation marks are described in Quotation Marks.
Valid and Invalid Literals
The following are examples of valid literals:
| ‘abc’ | Is a character string. |
| ‘ab”C’ | Is a character string. |
| ” | Is a null string. |
| 3.14159 | Is a number literal. |
| 9 | Is a number literal. |
| ‘10.99’ | Is a character string. |
| ‘John’s toy boat’ | Is a character string. |
| ‘ABCd_EfG’ | Is a character string. |
| ‘1234A’ | Is a character string. |
The following are examples of invalid literals:
| 1 23 | Spaces are not permitted in number literals. |
| $10.99 | Periods are not permitted in an unquoted character string, and the dollar sign is not permitted in a number literal. |
| ‘John’s toy boat’ | ‘John’ is a valid character string, but the rest of the line is invalid. |