How to filter Object using Array.prototype.filter?

Question

Given

var arr = [1,2,true,4,{\"abc\":123},6,7,{\"def\":456},9,[10]]

we can filter number items within array arr using N

Answer 1

In ES6 the following would do it for the example values you have listed:

arr.filter(Object.isExtensible)

Obviously, this will exclude objects that have been marked non-extensible, by a call to Object.freeze, Object.seal, or Object.preventExtensions. Unless you plan to use those, I believe this does the job.

var arr = [
    /* primitives: */
    2, true, "str", null, undefined, NaN, 
    /* objects */
    new Number(2), {a:1}, Object.create(null), [10], x=>x, new Date(), new Set()
];

var objects = arr.filter(Object.isExtensible);

console.log(objects);