如下打印结果
let arr = [1, 2];
arr[2] = 'a'
arr['3'] = 'b'
arr.foo = 'c'
arr['5'] = 'd'
console.log(arr);
console.log(arr.length);
如下打印结果
let arr = [1, 2];
arr[2] = 'a'
arr['3'] = 'b'
arr.foo = 'c'
arr['5'] = 'd'
console.log(arr);
console.log(arr.length);