AX / D365FO – Set a default value of a table field when creating a new row

To set a default value of a table field just use the initValue() method of the table

[ExtensionOf(tableStr(CustTable))]
final class CustTable_Table_Extension
{
    void initValue()
    {
        next initValue();

        this.yourField = 1234 //set your new custom field's default value.
    }