Prototype-chain Memes

So you're telling me that accessing an array with a negative index in JavaScript not only works but actually adds a property to the array? And then when you check the array, it shows you this cursed -1: 4 sitting there like it belongs? The bell curve perfectly captures the JavaScript experience: beginners think it's ridiculous (correct), experts also think it's ridiculous (also correct), but the middle crowd has Stockholm syndrome and will defend it with their lives. "It makes sense bro, everything in JS is an object!" Yeah, and that's exactly the problem. JavaScript treats arrays like objects because they are objects, so test[-1] = 4 is just adding a property named "-1" to your array object. It's technically in the spec, which somehow makes it worse.