diff --git a/array.c b/array.c
index aa52f3a..a47660c 100644
--- a/array.c
+++ b/array.c
@@ -40,7 +40,6 @@ static NODE **null_dump(NODE *symbol, NODE *subs);
 static afunc_t null_array_func[] = {
 	(afunc_t) 0,
 	(afunc_t) 0,
-	null_length,
 	null_lookup,
 	null_afunc,
 	null_afunc,
@@ -150,15 +149,6 @@ null_lookup(NODE *symbol, NODE *subs)
 	return symbol->alookup(symbol, subs);
 }
 
-/* null_length --- default function for array length interface */
-
-NODE **
-null_length(NODE *symbol, NODE *subs ATTRIBUTE_UNUSED)
-{
-	static NODE *tmp;
-	tmp = symbol;
-	return & tmp;
-}
 
 /* null_afunc --- default function for array interface */
 
@@ -618,6 +608,9 @@ do_delete(NODE *symbol, int nsubs)
 
 	(void) assoc_remove(symbol, subs);
 	DEREF(subs);
+	if (assoc_empty(symbol))
+		/* last element was removed, so reset array type to null */
+		null_array(symbol);
 
 #undef free_subs
 }
diff --git a/awk.h b/awk.h
index e3f458b..5a8da4e 100644
--- a/awk.h
+++ b/awk.h
@@ -542,29 +542,27 @@ typedef struct exp_node {
 #define xarray		sub.nodep.rn
 #define parent_array	sub.nodep.x.extra
 
-#define ainit		array_funcs[0]
 #define ainit_ind	0
-#define atypeof		array_funcs[1]
+#define ainit		array_funcs[ainit_ind]
 #define atypeof_ind	1
-#define alength		array_funcs[2]
-#define alength_ind	2
-#define alookup 	array_funcs[3]
-#define alookup_ind	3
-#define aexists 	array_funcs[4]
-#define aexists_ind	4
-#define aclear		array_funcs[5]
-#define aclear_ind	5
-#define aremove		array_funcs[6]
-#define aremove_ind	6
-#define alist		array_funcs[7]
-#define alist_ind	7
-#define acopy		array_funcs[8]
-#define acopy_ind	8
-#define adump		array_funcs[9]
-#define adump_ind	9
-#define astore		array_funcs[10]
-#define astore_ind	10
-#define NUM_AFUNCS	11		/* # of entries in array_funcs */
+#define atypeof		array_funcs[atypeof_ind]
+#define alookup_ind	2
+#define alookup 	array_funcs[alookup_ind]
+#define aexists_ind	3
+#define aexists 	array_funcs[aexists_ind]
+#define aclear_ind	4
+#define aclear		array_funcs[aclear_ind]
+#define aremove_ind	5
+#define aremove		array_funcs[aremove_ind]
+#define alist_ind	6
+#define alist		array_funcs[alist_ind]
+#define acopy_ind	7
+#define acopy		array_funcs[acopy_ind]
+#define adump_ind	8
+#define adump		array_funcs[adump_ind]
+#define astore_ind	9
+#define astore		array_funcs[astore_ind]
+#define NUM_AFUNCS	10		/* # of entries in array_funcs */
 
 /* Node_array_ref: */
 #define orig_array lnode
@@ -1345,7 +1343,7 @@ DEREF(NODE *r)
 extern jmp_buf fatal_tag;
 extern int fatal_tag_valid;
 
-#define assoc_length(a)	((*((a)->alength(a, NULL)))->table_size)
+#define assoc_length(a)	((a)->table_size)
 #define assoc_empty(a)	(assoc_length(a) == 0)
 #define assoc_lookup(a, s)	((a)->alookup(a, s))
 
@@ -1378,7 +1376,6 @@ extern const char *make_aname(const NODE *symbol);
 extern const char *array_vname(const NODE *symbol);
 extern void array_init(void);
 extern int register_array_func(afunc_t *afunc);
-extern NODE **null_length(NODE *symbol, NODE *subs);
 extern NODE **null_afunc(NODE *symbol, NODE *subs);
 extern void set_SUBSEP(void);
 extern NODE *concat_exp(int nargs, bool do_subsep);
diff --git a/cint_array.c b/cint_array.c
index 05b9440..7db45fd 100644
--- a/cint_array.c
+++ b/cint_array.c
@@ -62,7 +62,6 @@ static void cint_print(NODE *symbol);
 afunc_t cint_array_func[] = {
 	cint_array_init,
 	is_uinteger,
-	null_length,
 	cint_lookup,
 	cint_exists,
 	cint_clear,
diff --git a/int_array.c b/int_array.c
index 069e027..9f70517 100644
--- a/int_array.c
+++ b/int_array.c
@@ -49,7 +49,6 @@ static void grow_int_table(NODE *symbol);
 afunc_t int_array_func[] = {
 	int_array_init,
 	is_integer,
-	null_length,
 	int_lookup,
 	int_exists,
 	int_clear,
diff --git a/str_array.c b/str_array.c
index bc6584d..4972a92 100644
--- a/str_array.c
+++ b/str_array.c
@@ -59,7 +59,6 @@ static NODE **str_dump(NODE *symbol, NODE *ndump);
 afunc_t str_array_func[] = {
 	str_array_init,
 	(afunc_t) 0,
-	null_length,
 	str_lookup,
 	str_exists,
 	str_clear,
@@ -78,7 +77,6 @@ static NODE **env_clear(NODE *symbol, NODE *subs);
 afunc_t env_array_func[] = {
 	str_array_init,
 	(afunc_t) 0,
-	null_length,
 	str_lookup,
 	str_exists,
 	env_clear,