diff --git a/include/string/StringBuilder.h b/include/string/StringBuilder.h
index a3596b7..d9d0861 100755
--- a/include/string/StringBuilder.h
+++ b/include/string/StringBuilder.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "../collections/List.h"
+#include "../collections/Array.h"
 #include "str.h"
 
 typedef struct StringBuilder {
@@ -16,10 +17,11 @@ void StringBuilder_destroy(StringBuilder* b);
 void StringBuilder_removeFromEnd(StringBuilder* b, u32 count);
 void StringBuilder_append_char(StringBuilder* b, char c);
 void StringBuilder_append_cstr(StringBuilder* b, char* s);
-void StringBuilder_append_string(StringBuilder* b, str s);
+void StringBuilder_append_str(StringBuilder* b, str s);
 void StringBuilder_append_i64(StringBuilder* b, i64 a);
 void StringBuilder_append_u64(StringBuilder* b, u64 a);
 void StringBuilder_append_f64(StringBuilder* b, f64 a);
+void StringBuilder_append_memory(StringBuilder* b, Array mem);
 
 // adds '\0' to the buffer and returns pointer to buffer content
 str StringBuilder_getStr(StringBuilder* b);
diff --git a/include/string/str.h b/include/string/str.h
index b13a43f..2d83c49 100755
--- a/include/string/str.h
+++ b/include/string/str.h
@@ -6,7 +6,7 @@
 
 typedef struct str {
     char* data;
-    u32 size;
+    u32 size; // size of data in bytes without \0
     bool isZeroTerminated;
 } str;
 
diff --git a/src/string/StringBuilder.c b/src/string/StringBuilder.c
index 9130e24..cc9cac0 100755
--- a/src/string/StringBuilder.c
+++ b/src/string/StringBuilder.c
@@ -26,12 +26,15 @@ void StringBuilder_append_char(StringBuilder* b, char c){
 }
 
 
-void StringBuilder_append_string(StringBuilder* b, str s){
+void StringBuilder_append_str(StringBuilder* b, str s){
+    if(s.data == NULL)
+        return;
+    
     List_push_size(&b->buffer, s.data, s.size);
 }
 
 void StringBuilder_append_cstr(StringBuilder* b, char* s){
-    StringBuilder_append_string(b, str_construct(s, strlen(s), true));
+    StringBuilder_append_str(b, str_construct(s, strlen(s), true));
 }
 
 void StringBuilder_append_i64(StringBuilder* b, i64 n){
@@ -51,3 +54,14 @@ void StringBuilder_append_f64(StringBuilder* b, f64 n){
     sprintf(buf, "%lf", n);
     StringBuilder_append_cstr(b, buf);
 }
+
+void StringBuilder_append_memory(StringBuilder* b, Array mem) {
+    if(mem.data == NULL)
+        return;
+    
+    char buf[8];
+    for (u32 i=0; i < mem.size; i++) {
+        sprintf(buf, "%02x", ((u8*)mem.data)[i]);
+        StringBuilder_append_str(b, str_construct(buf, 2, true));
+    }
+}