Example of using JS to determine whether an element is an array

let a = [1,2,3,4,5,6];
 let b = [
 {name: 'Zhang Fei', type: 'tank'},
 {name: 'Guan Yu', type: 'soldier'},
 {name: 'Liu Bei', type: 'shooter'},
 ];
 let c = 123;
 let d = 'www';
 let e = {name: 'Angela', type: 'mage'};

console.log(Array.isArray(a)); // true
 console.log(Array.isArray(b)); // true
 console.log(Array.isArray(c)); // false
 console.log(Array.isArray(d)); // false
 console.log(Array.isArray(e)); // false

console.log(a instanceof Array); // true
 console.log(b instanceof Array); // true
 console.log(c instanceof Array); // false
 console.log(d instanceof Array); // false
 console.log(e instanceof Array); // false

console.log(e instanceof Object); // true

console.log(a.constructor === Array); // true
console.log(b.constructor === Array); // true

console.log(c.constructor === Number); // true
console.log(d.constructor === String); // true
console.log(e.constructor === Object); // true

console.log(Object.prototype.toString.call(a) === '[object Array]'); // true
console.log(Object.prototype.toString.call(b) === '[object Array]'); // true

console.log(Object.prototype.toString.call(c) === '[object Number]'); // true
console.log(Object.prototype.toString.call(d) === '[object String]'); // true
console.log(Object.prototype.toString.call(e) === '[object Object]'); // true

console.log(Array.prototype.isPrototypeOf(a)); // true
 console.log(Array.prototype.isPrototypeOf(b)); // true
 console.log(Array.prototype.isPrototypeOf(c)); // false
 console.log(Array.prototype.isPrototypeOf(d)); // false
 console.log(Array.prototype.isPrototypeOf(e)); // false