Using masks
Use masks to determine which codes must be selected.
The masks are created by using the following characters:
| $ | The number to be selected must end with the
character preceding the $ |
| ^ | The selection must start with the first
character |
| * | The preceding character must occur one or more
times |
| [5-9] | The character to be selected must be between 5
and 9 |
| [579] | The value of the character to be selected must
be 5, 7 or 9 |
| ... | The dots indicate the number of characters |
Example
The following codes are defined:
- 899011
- 899027
- 899031
- 899042
- 899135
- 899168
- 899281
- 899292
- 899315
To select codes 899031 and 899281, you must write: ^...[3-8]1$
To select codes 899135 and 899315, you must write: ^...[13]*5$