In Javascript, split is called to return an array that is not empty.

Today, I found a strange problem at work. In theory, it should be an array without elements. The length is actually 1. After checking for half a day, it turns out that the split in Javascript is different from other languages. That is, if you use split for a Null string, an array containing an empty string is returned instead of an empty array.

var str = "",

    arr = str.split("_");

console.log(arr.length === 1); //true

console.log(arr === []); //false

console.log(arr === [""]); //true

For more information, see MDN.

Note:When the string is empty,splitReturns an array containing one empty string, rather than an empty array.