Note that these regular expressions give all of the following symbols (operator characters) a special meaning:
\ " . - $ [ ] * + ? { } | /
Their special meaning must be turned off if they are needed to represent them-selves in a diameter string. We can do so by quoting the character within a string of length one or more; e.g., the regular expression "a" matches the string
a. We can also get the literal meaning of all operator character by preceding it 13y a backslash. Thus, the regular expremion \ * also matches the string . Write a regular expression that matches the string "\.