arrayname instanceof Array; isn't working as expected

Question

I was expecting something like "154, 544 true" but this is not working.

<p id="demo"></p>

<script>
  var n = [154, 45, 100, 544, 75], txt = "";
  var nFil = n.filter((value) => value > 100);
  txt = nFil.join(", ") + "<br>" + nFil instanceof Array;
  document.getElementById("demo").innerHTML = txt;
</script>

Answer 1

需要一个括号，如：

txt = nFil.join(", ") + "<br>" + (nFil instanceof Array);

Answer 2

I assume that you want to check a variable is an Array or not?

If yes, you can use this

Array.isArray(<variable_name>); // returns `true` if the variable is an Array, `false` otherwise

Complete reference: MDN