check if array is empty/undefined

[WarKirby]

Hi everyone, quick syntax question.

I'm manually defining some data (hardcoding) in a manner like this:

myArray = [[a,b,c], [], [1,2,3]];

A 2d array, note the empty array in the middle.
What i want to know, is how to check if one of these arrays is empty, before trying to load data from it. For example, do i use:

if (myArray[1] != null)

if (myArray[1] != undefined)

if (myArray[1].length != 0)

if (myArray[1] != [])

or something else i haven't thought of? What syntax do i need to successfully exclude that middle array and NOT read it ?

[laurence485]

Use .length property, if length is 0 then the array is empty

[Biodiscus]

Originally Posted by laurence485

Use .length property, if length is 0 then the array is empty

myArray.length. He tried myArray[1].length.

[WarKirby]

Originally Posted by Biodiscus

myArray.length. He tried myArray[1].length.

no, no. that was deliberate. I'm not checking myarray here, i'm checking the nested array that is in element 1 of myarray (which is empty)

[CyanBlue]

If you do a trace on the length property of each elements, you should get 3, 0, 3 for those three elements.

Since you are hardcoding it as [], it can never be null or undefined. So, you basically need to check the length of it and see if it is myArray[1].length > 0 and then go on from there.

for (var i:int = 0 ; i < myArray.length ; i++)
{
    trace(i + " : " + myArray[i].length);
    if (myArray[i].length > 0)
    {
        // This runs only for the first and last elements...
        doYourThing(myArray[i]);
    }
}