如何获取数组项的类型

const arr = [1, 'two', true];
console.log(typeof arr[0]); // 输出 "number"
console.log(typeof arr[1]); // 输出 "string"
console.log(typeof arr[2]); // 输出 "boolean"

const arr = [1, 'two', true];
console.log(Array.isArray(arr)); // 输出 true

const arr = [1, 'two', true];
console.log(arr[0] instanceof Number); // 输出 false
console.log(arr[1] instanceof String); // 输出 false
console.log(arr[2] instanceof Boolean); // 输出 false

const arr = [1, 'two', true];
console.log(Object.prototype.toString.call(arr[0])); // 输出 "[object Number]"
console.log(Object.prototype.toString.call(arr[1])); // 输出 "[object String]"
console.log(Object.prototype.toString.call(arr[2])); // 输出 "[object Boolean]"