awk array

UNIX for Beginners Q & A
1

Hello. I'm trying to figure out which one of these is not true about an awk array.

     -You do not need to formally declare an array; it is created automatically on first assignment       
         
                   -Array elements can only be addressed using an index       
  
   
                   -A for loop can itterate over all indexes or keys in an array       
  
   
                   -If an array element is accessed before it is assigned; the default value will be 0
2

"True" to all except for a "partial True" for the fourth questiion - in string context, the value of an undefined / uninitialized / unassigned element is "" , i.e. the empty string.