diff --git a/datastruct/deque.c b/datastruct/deque.c
index e1d385a..12e4393 100644
--- a/datastruct/deque.c
+++ b/datastruct/deque.c
@@ -76,7 +76,16 @@ bool deque_back(struct _deque* self, void* obj)
 
 bool deque_front(struct _deque* self, void* obj)
 {
+    assert(self != NULL);
+    assert(self->_head != NULL);
+    assert(obj != NULL);
 
+    if (self->empty(self))
+    {
+        return false;
+    }
+    memmove(obj, self->_head->prev->obj, self->_obj_size);
+    return true;
 }
 
 bool deque_insert(struct _deque* self, int index, void* obj)
@@ -143,7 +152,7 @@ void deque_print(struct _deque* self)
 
     uint32_t i = 0;
     struct _deque_node * node = self->_head->prev;
-    while (node != self->_head->next)
+    for (uint32_t i = 0; i < self->size(self); i++)
     {
         self->print_obj(node->obj);
         node = node->next;
diff --git a/datastruct/deque_test.c b/datastruct/deque_test.c
index 3bf8b9f..800ab0c 100644
--- a/datastruct/deque_test.c
+++ b/datastruct/deque_test.c
@@ -24,16 +24,26 @@ static void deque_test_num(void)
 	{
 		dq.push_back(&dq, &data[i]);
 
-		dq.back(&dq, &temp);
-
-		printf("push_back = ");
+		dq.front(&dq, &temp);
+		printf("front = ");
 		dq.print_obj(&temp);
-		printf("\tsize after push_back = %2d\n", dq.size(&dq));
+
+		dq.back(&dq, &temp);
+		printf("\tback = ");
+		dq.print_obj(&temp);
+
+		printf("\tsize = %2d\n", dq.size(&dq));
 	}
 	printf("----- print -----\n");
 	dq.print(&dq);
 	printf("\n");
 
+	dq.clear(&dq);
+	if (dq.empty(&dq))
+	{
+		printf("----- empty -----\n");
+	}
+
 #if 0
 	printf("----- pop -----\n");
 	for (i = 0; i < len + 1; i++)