Scope: I have been learning prototype inheritance in java script and I tried the following code in my web browser. I found something really interesting while executing the following code.

let animal = {
  eats: true
};
let rabbit = {
  jumps: true
};
const p=Object.create(rabbit)
rabbit.__proto__ = animal
let y=new Array(2,3)
console.log(Object.getPrototypeOf(y))
var val=y.find((b)=>(b==2));
console.log(val);
console.log(Array.isArray(y))
y.__proto__=rabbit
console.log(Array.isArray(y))
console.log(Object.getPrototypeOf(y))
var ccl=y.find((b)=>(b==2)); 

Question: I have created a array and printed its prototype and then called the find method of array and check whether it's an array using Array.isArray() method. Then I have assigned the prototype of y to rabbit object.

When I checked if it is still an array, I got true, but when calling the find method I get an error and on checking the prototype there was no functions of an array.

Then on what basis does the Array.isArray() method returns true.

Output:

[constructor: ƒ, concat: ƒ, copyWithin: ƒ, fill: ƒ, find: ƒ, …]at: ƒ at()concat: ƒ concat()constructor: ƒ Array()copyWithin: ƒ copyWithin()entries: ƒ entries()every: ƒ every()fill: ƒ fill()filter: ƒ filter()find: ƒ find()findIndex: ƒ findIndex()findLast: ƒ findLast()findLastIndex: ƒ findLastIndex()flat: ƒ flat()flatMap: ƒ flatMap()forEach: ƒ forEach()includes: ƒ includes()indexOf: ƒ indexOf()join: ƒ join()keys: ƒ keys()lastIndexOf: ƒ lastIndexOf()length: 0map: ƒ map()pop: ƒ pop()push: ƒ push()reduce: ƒ reduce()reduceRight: ƒ reduceRight()reverse: ƒ reverse()shift: ƒ shift()slice: ƒ slice()some: ƒ some()sort: ƒ sort()splice: ƒ splice()toLocaleString: ƒ toLocaleString()toString: ƒ toString()unshift: ƒ unshift()values: ƒ values()Symbol(Symbol.iterator): ƒ values()Symbol(Symbol.unscopables): {copyWithin: true, entries: true, fill: true, find: true, findIndex: true, …}[[Prototype]]: Object
2
true
true
{jumps: true}jumps: true[[Prototype]]: Objecteats: true[[Prototype]]: Objectconstructor: ƒ Object()hasOwnProperty: ƒ hasOwnProperty()isPrototypeOf: ƒ isPrototypeOf()propertyIsEnumerable: ƒ propertyIsEnumerable()toLocaleString: ƒ toLocaleString()toString: ƒ toString()valueOf: ƒ valueOf()__defineGetter__: ƒ __defineGetter__()__defineSetter__: ƒ __defineSetter__()__lookupGetter__: ƒ __lookupGetter__()__lookupSetter__: ƒ __lookupSetter__()__proto__: (...)get __proto__: ƒ __proto__()set __proto__: ƒ __proto__()
Uncaught TypeError: y.find is not a function
    at <anonymous>:17:11