# Creating complex expressions

If you have complex expressions to create, or advanced changes to be carried out on the output flow, then the Expression Builder interface can help in this task.

## Procedure

1. Click the Expression field of your input or output table to display the [...] button.
2. Then click this three-dot button to open the Expression Builder.

   For more information regarding the Expression Builder, see [Writing code using the Expression Builder](https://help.qlik.com/talend/en-US/studio-user-guide/8.0/writing-code-using-expression-builder).