diff --git a/include/std.h b/include/std.h
index 25b9661..27416e8 100755
--- a/include/std.h
+++ b/include/std.h
@@ -20,6 +20,7 @@ typedef int64_t i64;
 typedef uint64_t u64;
 typedef float f32;
 typedef double f64;
+typedef void* ptr;
 
 #if !__cplusplus
 typedef u8 bool;
@@ -33,7 +34,7 @@ typedef const char* cstr;
 
 #define nameof(V) #V
 
-#define ARRAY_SIZE(A) (sizeof(A)/sizeof(A[0]))
+#define ARRAY_LEN(A) (sizeof(A)/sizeof(A[0]))
 #define ALIGN_TO(_SIZE,_ALIGN)        (((_SIZE) + ((_ALIGN) - 1)) & ~((_ALIGN) - 1))
 
 #if defined(_WIN64) || defined(_WIN32)
diff --git a/include/string/StringBuilder.h b/include/string/StringBuilder.h
index d9d0861..726251d 100755
--- a/include/string/StringBuilder.h
+++ b/include/string/StringBuilder.h
@@ -21,7 +21,7 @@ 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);
+void StringBuilder_append_memory(StringBuilder* b, Array mem, bool uppercase);
 
 // 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 2d83c49..4fe479e 100755
--- a/include/string/str.h
+++ b/include/string/str.h
@@ -3,6 +3,7 @@
 #include "../std.h"
 #include "char.h"
 #include "cstr.h"
+#include "../collections/Array.h"
 
 typedef struct str {
     char* data;
@@ -11,7 +12,7 @@ typedef struct str {
 } str;
 
 /// creates str from a string literal
-#define STR(LITERAL) str_construct(LITERAL, ARRAY_SIZE(LITERAL) - 1, true)
+#define STR(LITERAL) str_construct(LITERAL, ARRAY_LEN(LITERAL) - 1, true)
 
 #define str_construct(DATA, LEN, ZERO_TERMINATED) ((str){ .data = DATA, .size = LEN, .isZeroTerminated = ZERO_TERMINATED })
 
@@ -41,3 +42,5 @@ u32 str_hash32(str s);
 
 str str_toUpper(str src);
 str str_toLower(str src);
+
+str hex_to_str(Array buf, bool uppercase);
\ No newline at end of file
diff --git a/src/string/StringBuilder.c b/src/string/StringBuilder.c
index cc9cac0..b13227e 100755
--- a/src/string/StringBuilder.c
+++ b/src/string/StringBuilder.c
@@ -55,13 +55,13 @@ void StringBuilder_append_f64(StringBuilder* b, f64 n){
     StringBuilder_append_cstr(b, buf);
 }
 
-void StringBuilder_append_memory(StringBuilder* b, Array mem) {
+void StringBuilder_append_memory(StringBuilder* b, Array mem, bool uppercase) {
     if(mem.data == NULL)
         return;
     
     char buf[8];
     for (u32 i=0; i < mem.size; i++) {
-        sprintf(buf, "%02x", ((u8*)mem.data)[i]);
+        sprintf(buf, uppercase ? "%02X" : "%02x", ((u8*)mem.data)[i]);
         StringBuilder_append_str(b, str_construct(buf, 2, true));
     }
 }
diff --git a/src/string/str.c b/src/string/str.c
index 748b0a5..83e7fec 100755
--- a/src/string/str.c
+++ b/src/string/str.c
@@ -1,4 +1,5 @@
 #include "string/str.h"
+#include "string/StringBuilder.h"
 
 str str_copy(str src){
     if(src.data == NULL || src.size == 0)
@@ -123,3 +124,9 @@ str str_toLower(str src){
     }
     return r;
 }
+
+str hex_to_str(Array buf, bool uppercase){
+    StringBuilder sb = StringBuilder_alloc(buf.size * 2 + 1);
+    StringBuilder_append_memory(&sb, buf, uppercase);
+    return StringBuilder_getStr(&sb);
+}