forEach is not a function error with JavaScript array

Question

I\'m trying to make a simple loop:

const parent = this.el.parentElement
console.log(parent.children)
parent.children.forEach(child => {
  console.log(chil         


        

Answer 1

First option: invoke forEach indirectly

The parent.children is an Array like object. Use the following solution:

const parent = this.el.parentElement;

Array.prototype.forEach.call(parent.children, child => {
  console.log(child)
});

The parent.children is NodeList type, which is an Array like object because:

• It contains the length property, which indicates the number of nodes
• Each node is a property value with numeric name, starting from 0: {0: NodeObject, 1: NodeObject, length: 2, ...}

See more details in this article.

---

Second option: use the iterable protocol

parent.children is an HTMLCollection: which implements the iterable protocol. In an ES2015 environment, you can use the HTMLCollection with any construction that accepts iterables.

Use HTMLCollection with the spread operatator:

const parent = this.el.parentElement;

[...parent.children].forEach(child => {
  console.log(child);
});

Or with the for..of cycle (which is my preferred option):

const parent = this.el.parentElement;

for (const child of parent.children) {
  console.log(child);
}