Set value for all rows in a datatable without for loop

Question

I'm trying to set the same value for all rows for a single column in a datatable without using for loop. Can anyone suggest any faster methods to achieve the same.

Answer 1

yes, this is possible, even without loop! This can be done with Expression property. Keep in mind that string values should be quoted, otherwise it sees this as another columnname.1

This will set the column 'col1' with the string value a:

preview.Columns["col1"].Expression = "'a'";

This will display in 'col1' the value of the column 'col2':

preview.Columns["col1"].Expression = "col2";

Answer 2

Have you considered removing and re-adding the column with a default value?

dt.Columns.Remove("FilterText")
dt.Columns.Add(New DataColumn() With {.ColumnName = "FilterText",
                                      .DataType = GetType(String),
                                      .DefaultValue = "Jam and chips"})

(assuming your column name is FilterText, and you want to set it to "Jam and chips")