resize method
Implementation
void resize(int? arg) {
int n ;
if(null == arg){
n =0;
}
else{
n = arg;
}
//
// If array did not previously contain enough space, allocate
// the necessary additional space. Otherwise, if the array had
// more blocks than are needed, release the extra blocks.
//
if (n > _size) {
do {
allocateMoreSpace();
} while (n > _size);
}
top = n;
}