Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Hi, May I read in an expression and then used it in the 'IF' or 'WHILE' or 'CASE'? For example, may I define the expression first, then use it? Or read in expressions from standard input or input files? expr1=' a gt 3' if(expr1) then do begin ****** endif It seems if I define 'expr1' as a string, and it is always true.. What type should it be? May I use something like: readf, in_unit, expr1 or readf, expr1, prompt='Enter Condition:' so, the 'expr1' can be defined more flexiable. Thanks Q