NAN and Infinity in javascript mathematical operations [duplicate]

Question

0 / 0 outputs NaN while 1 / 0 outputs Infinity

How javascript evaluates the first mathematical operation?

Answer 1

As per spec

0 / 0 outputs NaN because

Division of a zero by a zero results in NaN; division of zero by any other finite value results in zero, with the sign determined by the rule already stated above.

and 1 / 0 outputs Infinity because

Division of a nonzero finite value by a zero results in a signed infinity. The sign is determined by the rule already stated above.

Point 7 and 8 in the section 12.6.3.2 Applying the / Operator (unordered list)