// big number 1000000000000000000000000000.0 => float n; // overflow it repeat( 20 ) n *=> n; // test it <<< Math.isinf( n ) >>>; // bye sanity 0 *=> n; // test it <<< Math.isnan( n ) >>>; // more <<< 1.0 / 0.0 => Math.isinf >>>; <<< 0.0 / 0.0 => Math.isnan >>>; <<< Math.INFINITY, -Math.INFINITY >>>; <<< Math.INFINITY => Math.isinf >>>;