As Extract Variable, the Extract Constant refactoring lets you extract a specified value to a corresponding constant.
The animation below demonstrates how to extract a specific word from a string to a constant:
To extract a constant:
Select a value to refactor or place a caret at a string containing the required value.
(Optional) If you place a caret at a place containing several expressions available for extracting, select the required expression and press Enter:
(Optional) If more than one occurrence of the expression is found, specify whether you wish to replace only the selected occurrence or all the found occurrences with the new variable:
Specify the constant name and press Enter.