To create a zero-filled JavaScript array, use the Unit8Array typed array.
Example
You can try to run the following code:
<html>
<body>
<script>
var arr1 = ["marketing", "technical", "finance", "sales"];
var arr2 = new Uint8Array(4);
document.write(arr1);
document.write("<br>Zero filled array: "+arr2);
</script>
</body>
</htmlOutput
marketing,technical,finance,sales Zero filled array: 0,0,0,0