Regular expressions are constructed in the same way that arithmetic expressions are created. That is, small expressions are combined using a variety of metacharacters and operators to create larger expressions.

You construct a regular expression by putting the various components of the expression pattern between a pair of delimiters. For JScript, the delimiters are a pair of forward slash (/) characters. For example:

/expression/

For VBScript, a pair of quotation marks ("") delimit regular expressions. For example:

"expression"

In both of the examples shown above, the regular expression pattern (*expression*) is stored in the **Pattern** property of the **RegExp** object.

The components of a regular expression can be individual characters, sets of characters, ranges of characters, choices between characters, or any combination of all of these components.