Removes nulls from the values of the column you apply this operation to. You have the option of replacing null values with one or more characters.
You can either:
right-click on a field
click the drop down of a field
then select Clean > Replace Null Values in the context menu that displays.
The corresponding dialog of the field you selected displays.
Enter the characters you wish to replace nulls with.
In this example, Amount is the original column. The Replace Null Values operation was used to remove the null values (n/a) and replace with 0 to produce the resulting values in the column Amount Replace Null.