Find and replace data which contain certain value range in specific column in JSL

[#1]

Hi! all,

I would like to find and replace data which contain certain value range in specific column by using jmp script

However, the code didn't take effect 

Here is my code that want to loop through the data in "mark" column and look for value that more than 1000 and substitute with 99

Names Default To Here( 1 );
dt = Data Table( "studentmark" );

headerList = dt << get column names( string );

For( i = 1, i <= N Items( headerList ), i++,

	If(  Contains(headerList[i], "mark"), 
	dt << Begin Data Update;
	For Each Row( dt, As Column( dt, headerList[i]) = Substitute( As Column( dt, headerList[i]) > 1000 , 99 ));
	dt << End Data Update;
	);	
	
);

Does anyone knows what's went wrong with the code? 

Appreciate the helps. Thank you

[#2 · Accepted solution]

I am assuming that you want all values above 1000 converted to 99, if so, the below script will do this more efficiently than using a For Each Row()

Names Default To Here( 1 );
dt = Data Table( "studentmark" );

headerList = dt << get column names( string );

For( i = 1, i <= N Items( headerList ), i++,
	If( Contains( headerList[i], "mark" ),
		theRows = dt << get rows where( As Column( headerList[i] ) > 1000 );
		If( Length( theRows ) > 0,
			Column( headerList[i] )[theRows] = 99
		);
	);	
);