Erased deallocates an array and clears its header. For a string array, this function also deallocates space used by the array’s elements. Erases clears the elements of an array. For a numerical array, this function sets to zero the array’s elements. For a string array, this function sets the string length to zero and deallocates space used by the array’s elements. It is not an error to erase an erased array. These functions implement the ERASE statement and dynamic array deallocation.
Ubound returns the upper bound for dimension dim. Dimensions are numbered starting with one. This function implements the BASIC UBOUND function.
from The Basmark QuickBASIC Programmer’s Manual by Lawrence Leinweber