Which of the following is not a within$-$table text calculation?

Counting the number of different cells in a text field. For example, counting the different values in the Country field.

Extracting a substring for a text field. For example, extracting the area code $302$ from telephone number $302-200-5731.$ Combining two text fields, such as combining a customer's first name John, and last name Doe, resulting in John Doe.

Replacing a number of characters in a text field, such as replacing $"$str$"$ with "street" in an address field.