checking for nulls in arrays

I have an array that’s missing some values it may look like this
myarray ,3,4,5
I want to check to see if myarray[0] is missing or not. How do I do that.
I’ve tried creating an if statement with if(myarray[0]==“Null”) or NULL or Null or Undefined but doesn’t seem to work.

Thanks,
Dan

Try it without the citation marks.

if (myarray[0] == null)

What type of objects are the values in your array?

Certain types, like ints and floats, can never be null.