Answer:
Yes. This shows that any one out of a choice of several characters can match the transition.
Yes. This shows that any one out of a choice of several characters can match the transition.
Rule 2. Choice of Character
If you want to match one of several characters,
place the characters inside square brackets, [].
Any number of characters can be put inside the brackets,
however the expression matches just one character at a time.
For example, [abc] matches just one character,
'a' or 'b' or 'c'.
Any number of bracketed groups can appear in a RE.
| Regular Expression | Matches | Does Not Match | ||||
|---|---|---|---|---|---|---|
[wW] | w | W | wW | [W | ] | |
[abc] | a | b | c | ab | ac | c] |
[dD]agmar | dagmar | Dagmar | dDagmar | agmar | dAgMar | |
[abc]d[EFG] | adE | cdG | bdF | aE | adg | dEF |
The characters inside the square brackets can appear in any order,
but a given character should appear only once per set of brackets.
So [abc] is equivalent to [cab].
The RE [aba] is a mistake,
but will usually be regarded as equivalent to [ab].
Does [wW][hH][yY] match wHy ?
(There are no spaces in the regular expression; your web browser might not show this clearly.)