How to turn an array into an object, js?

Question

JavaScript

Good afternoon! Can you please tell me how to turn an array into an object?
Why doesn't this code work?

const toObj = (arr) => {
  let obj = {};
  return arr.forEach((e) => {
   obj = { ...e };
  });
};

An array like this

const arr = [
{test: []}
{test2: []}
...
]

need this

const arr = {
test: []
test2: []
...
}

Why doesn't the spread operator work?
Thank you!

Answer 1

The fact is that in each iteration inside forEach you overwrite the obj object completely (and not expand / supplement it), so that in the last iteration in the obj object there will be only those properties / values ​​\u200b\u200bthat the last element of the array had. Better this way:

const toObj = (arr) => arr.reduce((a, b) => ({ ...a, ...b }));

Answer 2

Here I will leave few people to account. Through reduce it is difficult to understand.

const arr = [
    { test: [1] },
    { test2: [2] },
  ];
let obj = {};
arr.forEach((el) => {
    Object.assign(obj,el);
});

console.dir(obj);