Programming ColdFusion MX, 2nd Edition

Name

Duplicate

Synopsis

                  
                  Duplicate(variable)

Creates a duplicate copy of variable without any references to the original. variable can be any ColdFusion datatype with the exception of component objects (COM, CORBA, and Java). Duplicate( ) overcomes problems associated with copying structures and queries. Generally, when copying a structure or query, any future change to the original object results in a change to the copy. Duplicate( ) eliminates this by making an independent copy of the original object. The duplicate copy isn’t affected by changes to the original. The Duplicate( ) function is especially useful for copying nested structures and XML objects, and should be used in place of the StructCopy( ) function. The following example illustrates the difference between copying and duplicating query objects:

<!--- create a query object ---> <cfset Products = QueryNew("ProductName, Color")> <cfset NewRows = QueryAddRow(Products, 1)> <cfset QuerySetCell(Products, "ProductName", "Widget", 1)> <cfset QuerySetCell(Products, "Color", "Silver", 1)> <!--- create a copy and a duplicate of the query ---> <cfset CopyProducts = Products> <cfset DuplicateProducts = Duplicate(Products)> <cfoutput> <b>Original:</b> You selected a #Products.Color# #Products.ProductName#.<br> <cfset QuerySetCell(Products, "Color", "Black", 1)> <b>Copy:</b> You selected a #CopyProducts.Color# #CopyProducts.ProductName#.<br> <b>Duplicate:</b> You selected a #DuplicateProducts.Color# #DuplicateProducts.ProductName#. ...