It seems like if performing multiple statements, only the "last" eval result is used as the conditional.

if (true, true,  false) alert(true); else alert(false);  (false)
if (false,false, A = 1) alert(true); else alert(false);  (true)

maybe like:

if (eval('false;false;A=1')) alert(true); else alert(false);  (true)
if (eval('true ; true;A=0')) alert(true); else alert(false);  (false)

Use: I needed a case insensitive Array/Object Search. (using get/set)

A = {Apple:12.3,Pear:34.5,Peach:3.22};
if (A.find = "pear",  A.found) alert(A.key + ' = ' + A.value);  (Pear = 34.5)