created at 2023/08/05 04:08:59
updated at 2023/08/05 04:09:18
JavaScript
// 如何判断一个变量是否为数组类型?
const arr = [1, 2, 3];
// todo 01
const is = Array.isArray(arr);
console.log(is);
// todo 02
console.log(arr instanceof Array);
// todo 03
console.log(Object.prototype.toString.call(arr));
// write a function to check if a variable is an array
function isArray(arr) {
return Object.prototype.toString.call(arr) === '[object Array]';
}