Question

% set HI 1
1
% if { [ info exists HI] && { $HI == 1 } } { puts "Hello World "}
can't use non-numeric string as operand of "&&"
%   

Either of the conditions can be tested alone. How to make the && of the tests work in TCL?

This alone works

% if  { $HI == 1 }  { puts "Hello World "}
Hello World

And this works alone too.

% if { [ info exists HI]  } { puts "Hello World "}
Hello World

Answer 1

You don’t need the extra curly braces; this should work fine:

if { [info exists HI] && $HI == 1 } { puts "Hello World" }