Update Sharepoint list column using column name with Office 365

@Sreelatha278

For that you can get the required index by using a for loop on the retrieved values

Listitem.fields

And then use if condition to check the fieldname currentitem.DisplayName.Equals("Requiredname")

And on then side use the assign as needed

Or you can directly use this in assign

ListItem.Fields.Where(function(x) x.DisplayName.Equals("Display Name of Field"))(0).Value = "Value to be updated"

instead of displayname use name if you want to use the backend names of the fields

Cheers