When an array needs to be cleared, many people use the following method:
a = [];
We know that JavaScript variable storage methods are divided into reference types and direct quantities. Arrays belong to objects, that is, reference types, and they refer to variable pointer addresses. The reason why they are designed this way is to save memory.
As for the above method of emptying an array, if you directly assign a new array, the previously referenced array may not be released (there are other references), such as the following code:
var a = [2,3];
var b = a;
a = [];
console.log(b);
At this time a and b are not the same array and are cleared. a and b still point to the previous reference address. Unless you do it intentionally, there will be hidden dangers.
So the best way to empty an array is to set length to 0, that is:
a.length = 0;
Reprinted from JS8.IN ™
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