JavaScript - Undefined Infinity or Not a Number?

Had a heated discussion with a friend about a particular expression and so this blog with ready references for some basic JavaScript expressions.

Expression	Value
Infinity	Anything beyond +/-1.7976931348623157e+308
typeof Infinity	"number"
typeof NaN	"number"
typeof undefined	"undefined"
typeof null	"object"
Infinity + Infinity	Infinity
Infinity - Infinity	NaN
-Infinity + Infinity	NaN
Infinity / Infinity	NaN
Infinity * Infinity	Infinity
Infinity * 1	Infinity
Infinity / 1	Infinity
Infinity / 0	Infinity
Infinity * 0	NaN
Infinity - 1e308	Infinity
Infinity - 1e309	NaN
-Infinity + 1e308	-Infinity
-Infinity + 1e309	NaN
Infinity / 1e308	Infinity
1 * "a"	NaN
1 + NaN	NaN
1 * NaN	NaN
undefined + 1	NaN
undefined * 1	NaN
undefined + Infinity	NaN
undefined * Infinity	NaN
undefined + NaN	NaN
undefined * NaN	NaN
undefined + null	NaN
undefined * null	NaN
1 + null	1
1 * null	0
null + null	0
null * null	0
Infinity + null	Infinity
Infinity * null	NaN
NaN + null	NaN
NaN * null	NaN
"" + Infinity	"Infinity"
"" + NaN	"NaN"
"" + null	"null"
"" + undefined	"undefined"

Having fun yet ?