javascript - How to determine the length of empty array elements in JS

Question

Object.prototype.toString.call(val) == '[object Array]' ? val.some(e => e != undefined && e != null && e != '') : false;

val is the array after the splice(0, 1) operation. I want val.some to return in the situation shown below. false

Answer 1

Array.prototype.some will skip elements with value undefined

If you need to consider undefined, you need to write a for loop to traverse it.

Answer 2

If indeed some, the callback method will not be executed.