Checking if a variable is an array

[d.healey]

var noteLetters = ["C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"];
Console.print("INFO: " + (noteLetters.constructor === Array));

The above code prints 0 (or undefined if cast to string). Any idea where I'm going wrong?

I've also tried the following but HISE doesn't seem to like it.

Console.print("INFO: " + (noteLetters instanceof Array));

I've also tried the standard .isArray which didn't work, I tried it as a function too but HISE didn't recognise it. I also tried declaring the array with the "new Array" method.

[Christoph Hart]

That's the part of the Javascript engine which is not fully standard compliant. I actually never used the new keyword. It also doesn't support prototypes (which I am assuming the .constructor property is).

But there are multiple ways to get to your solution. The fastest would be to check if the variable has a property "length", which is

var array = ["C", 1, 2];
var x = 24;
var empty = [];

var object = {};

object.property = 12;

function isArray(variable)
{
	return !(variable.length === undefined); // === operator to catch empty arrays
};

Console.print(isArray(x)); // 0
Console.print(isArray(array)); // 1
Console.print(isArray(empty)); // 1
Console.print(isArray(object)); // 0

[d.healey]

I thought about that but strings also have a length property so I would need an extra check too make sure it wasn't a string. I'll make a little function that does both checks thanks for the quick response

[Christoph Hart]

Oops, I forgot about strings in my little test suite

function isArray(variable)
{
   return !(variable.length === undefined) && typeof(variable) != "string";
};

This should do the trick…