Create New Column if the list contains

[#1]

Hi,

I have a list which contains column names. I want to create a new column if the column name exist in the string list.

Here's my code. It works but creates duplicate column names bc of the loop. Any advice?

Names Default To Here( 1 );
Clear Globals();
Clear Log();
dt = Current Data Table();

col_list = dt << Get Column Names( string );

idds = {52,54};
For( i = 1, i <= N items( idds ), i++,

  If( Contains( col_list, Char( idds[i] ) ),
   dt<<Column( "%_IDD", Numeric, "Continuous", Format( "Percent", 12, 2 ));
  ););
  

 Thanks

[#2 · Accepted solution]

Your code will create a new column for every column found in your idds list.  This code checks to see if the column already exists and if it doesn't it will create it.

Names Default To Here( 1 );
Clear Globals();
Clear Log();
dt = Current Data Table();

col_list = dt << Get Column Names( string );

idds = {52, 54};
For( i = 1, i <= N Items( idds ), i++, 

	If(
		Contains( col_list, Char( idds[i] ) ) & Try( Column( dt, "%_IDD" ) << get name, "" ) ==
		"",
		dt << New Column( "%_IDD", Numeric, "Continuous", Format( "Percent", 12, 2 ) )
	)
);