How to replace null values in a column with "0"

Fine in that case
–hope you have a datatable ready and lets name it outdt
–now use a for each row loop and pass that variable as input
–inside this use a if condition like this
String.IsNullOrEmpty(row(“yourcolumnname”).ToString)
if true goes to THEN part where use a assign activity like this
row(“yourcolumnname”) = “0”

Cheers @AryanSingh