Hello can some one help me with this syllogism using if statements in javascript

Question

All men are mortals.
Socrates is a man.
There for Socrates is a mortal.

Answer 1

Something like this roughly lines up.
var socrates ={'sex': 'man'};
if (socrates.sex === 'man' )
socrates.isMortal = true;

If socrates is not a man, it is unknown whether socrates is mortal or not so I didn't set isMortal to false in an else section.