How does JavaScript evaluate greater-than and less-than operations?

Question

More specifically, greater-than-or-equal-to operations.

Logically n >= k should be equal to n > k || n == k but that doesn't seem to be the case.

Why is it that this:

var d1 = new Date(2018, 1, 16);
var d2 = new Date(2018, 1, 16);
console.log(d1 > d2);
console.log(d1 < d2);
console.log(d1 == d2);
console.log(d1 >= d2);
console.log(d1 <= d2);

produces false, false, false, true, true ?

Answer 1

 console.log(d1 > d2);
 console.log(d1 < d2);

These convert them to numbers first, then compare them. As they are at the same time, they got the same number so one is not bigger or smaller than the other.

 console.log(d1 == d2);

This checks if the date references are the same. But they are not as they are two different objects.

 console.log(d1 >= d2);
 console.log(d1 <= d2);

These compare them by numbers, but also for equality. If you do:

 console.log(+d1 === +d2);

you see that they are equal by the number they represent.

Reference: == <=

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TLDR: use === and manually convert types to prevent such odd behaviour...