var age, ref; age = prompt("How old are you?", 0); if (age >= 18) { alert('Adult'); } else { alert('Under 18'); } if (age < 15) { alert('Under 15'); } if (age < 16) { alert("Under age"); } else { alert("Of age"); } // Doesn't do what one would expect. At all. Look at the JS. console.log((ref = age < 15) != null ? ref : { "Minor": "Elder" }); //# sourceMappingURL=3-1-conditions.js.map