Array.prototype.toString = function(){
console.log("");
}
var arr = [1,2,3];
arr.toString();
console.log(Object.prototype.toString.call(arr));
after the toString of the array is rewritten, the method of the array is called directly, and the method after the rewrite will be executed, but the toString on the object prototype will not be modified. We know that Array is also an object, and the method of Array can be inherited from the object Object, so what is the relationship between the object and the array? Is an array an instance of an object? Or what? Ask the great god for help in the analysis