This post is part of a series called Guess the JavaScript Output
And today's question is a bit tricky one:

What will be the output of the following code?

let a = {};
let b = { key: "b" };
let c = { key: "c" };

a[b] = 123;
a[c] = 456;

console.log(a[b]);

Uncle Mike solved this within 20s (Mike started coding in the womb and has built his own OS called MikeOS).
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