How can I iterate over properties in a JavaScript object?

How can I iterate over properties in a JavaScript object?

You can use a for...in loop, Object.keys(), or Object.entries() to iterate over properties.

Can you show me an example using Object.keys()?

Sure! Here's a simple example:

const obj = { a: 1, b: 2, c: 3 };
Object.keys(obj).forEach(key => {
    console.log(key, obj[key]);
});

What about using for...in? Is it different?

Yes, with for...in, you can do it like this:

for (let key in obj) {
    console.log(key, obj[key]);
}

Just be cautious of inherited properties!

Thanks! Are there any performance differences between these methods?

Yes, generally, for...in can be slower due to prototype chain checks, while Object.keys() is often faster for direct properties.