Principle of object. Prototype. ToString. Call()

let a={
	a:1
}
let b=[2,3]
console.log(a.toString())
console.log(b.toString())
//[object Object], Output a Data type of 
//2,3   Convert the values in the array into strings 

js In fact, it rewrites some data types toString Method , That's why the above situation is created ,array Has its corresponding toString Method , Called nearby

let a={
    a:1
}
let b=[2,3]
delete Array.prototype.toString
console.log(a.toString())
console.log(b.toString())

This will output [object Object] [object Array]

The elegant way is , Let the data of the variable you want to judge call Object.prototype.toString Methods , In this way, you can accurately judge the type of variables