Iterate over JavaScript object with index

Question

I am trying to loop over a JavaScript object in ES6.

 for (let [value, index] of object) {     do something with rest     if (index >= 1) {        // do something with first item     }   } 

It works fine, although when I try to use index to get the first item it returns an error in console:

Uncaught TypeError: Invalid attempt to destructure non-iterable instance 

Any ideas on how to loop over an object with index? thanks

Answer 1

This is just meant to be an addition to jonas w's solutions.

If you need the key of the current value:

const object = {a:2, b:4, c:6, d:8};    for (const [index, [key, value]] of Object.entries(Object.entries(object))) {    console.log(`${index}: ${key} = ${value}`);  }    Object.entries(object).forEach(([key, value], index) => {    console.log(`${index}: ${key} = ${value}`);  });

Of course, you can leave out the key at any time:

const object = {a:2, b:4, c:6, d:8};    for (const [index, [, value]] of Object.entries(Object.entries(object))) {    console.log(`${index}: ${value}`);  }    Object.entries(object).forEach(([, value], index) => {    console.log(`${index}: ${value}`);  });