If you’ve spent more than five minutes writing JavaScript, you’ve probably had a moment where you stared at your screen and whispered, “...why?”
function showThis() { console.log(this); } showThis(); // window (or undefined in strict mode)
So next time you see [] + [] returning "" , don’t cry. Laugh. Then fix it. And remember: you’re not alone. What’s the weirdest JavaScript bug you’ve ever encountered? Hit reply or drop a comment—I’d love to compare war stories.
You are not alone. JavaScript is the quirky, misunderstood genius of the programming world. It was built in 10 days, it drives the modern web, and it has a list of "features" that look more like bugs.
console.log([] + []); // "" (empty string) console.log([] + {}); // "[object Object]" console.log({} + []); // 0 (wait, WHAT?) The last one is a parsing quirk. In some engines, {} at the start of a line is treated as an empty block, not an object. So {} + [] becomes + [] which coerces to 0. Never, ever trust == . It’s like asking a toddler if two things are the same.
If you’ve spent more than five minutes writing JavaScript, you’ve probably had a moment where you stared at your screen and whispered, “...why?”
function showThis() { console.log(this); } showThis(); // window (or undefined in strict mode) js the weird parts
So next time you see [] + [] returning "" , don’t cry. Laugh. Then fix it. And remember: you’re not alone. What’s the weirdest JavaScript bug you’ve ever encountered? Hit reply or drop a comment—I’d love to compare war stories. If you’ve spent more than five minutes writing
You are not alone. JavaScript is the quirky, misunderstood genius of the programming world. It was built in 10 days, it drives the modern web, and it has a list of "features" that look more like bugs. And remember: you’re not alone
console.log([] + []); // "" (empty string) console.log([] + {}); // "[object Object]" console.log({} + []); // 0 (wait, WHAT?) The last one is a parsing quirk. In some engines, {} at the start of a line is treated as an empty block, not an object. So {} + [] becomes + [] which coerces to 0. Never, ever trust == . It’s like asking a toddler if two things are the same.
