The significance of void 0 in JS

What

void: prefix operator
void 0 will return undefined as well

Why

Why using void 0 alternative to undefined?
Because undefined is a global variable:
In early, you can change the undefined directlty

console.log(undefined) // Output: "undefined"
var undefined = "I am new value"
console.log(undefined) // Output: "I am new value"

Now, the undefined is set read-only, but you still change it in local scope

{
	const undefined = "I am new value"
	console.log(undefined) // Output: "I am new value"
}

It will be significant that avoiding certain exception by using void 0.
Meanwhile, another trivial advantage is void will occupies less byte compared with undefined.

Summary

1. Avoid exception sinceundefined is a global variable can be changed arbitrarily under some conditions.
2. occupy less byte

Reference

https://stackoverflow.com/questions/7452341/what-does-void-0-mean