diff --git a/go.mod b/go.mod
index cba9744..9997a3a 100644
--- a/go.mod
+++ b/go.mod
@@ -7,4 +7,10 @@ require (
 	github.com/spf13/pflag v1.0.5
 )
 
-require golang.org/x/sys v0.0.0-20220818161305-2296e01440c6 // indirect
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.8.1 // indirect
+	golang.org/x/sys v0.0.0-20220818161305-2296e01440c6 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/go.sum b/go.sum
index 58b395d..d71b971 100644
--- a/go.sum
+++ b/go.sum
@@ -4,8 +4,24 @@ github.com/chzyer/readline v1.5.1 h1:upd/6fQk4src78LMRzh5vItIt361/o4uq553V8B5sGI
 github.com/chzyer/readline v1.5.1/go.mod h1:Eh+b79XXUwfKfcPLepksvw2tcLE/Ct21YObkaSkeBlk=
 github.com/chzyer/test v1.0.0 h1:p3BQDXSxOhOG0P9z6/hGnII4LGiEPOYBhs8asl/fC04=
 github.com/chzyer/test v1.0.0/go.mod h1:2JlltgoNkt4TW/z9V/IzDdFaMTM2JPIi26O1pF38GC8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220818161305-2296e01440c6 h1:Sx/u41w+OwrInGdEckYmEuU5gHoGSL4QbDz3S9s6j4U=
 golang.org/x/sys v0.0.0-20220818161305-2296e01440c6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/object/object.go b/object/object.go
index 18492ea..82df34b 100644
--- a/object/object.go
+++ b/object/object.go
@@ -429,3 +429,32 @@ func AnyToObject(a any) Object {
 	}
 	return NIL
 }
+
+func ObjectToAny(o Object) any {
+	switch v := o.(type) {
+	case *Boolean:
+		return v.Value
+	case *String:
+		return v.Value
+	case *Integer:
+		return v.Value
+	case *Float:
+		return v.Value
+	case *Array:
+		array := make([]any, len(v.Elements))
+		for idx, element := range v.Elements {
+			array[idx] = ObjectToAny(element)
+		}
+		return array
+	case *Hash:
+		hash := make(map[any]any)
+		for _, pair := range v.Pairs {
+			key := ObjectToAny(pair.Key)
+			if key != nil {
+				hash[key] = ObjectToAny(pair.Value)
+			}
+		}
+		return hash
+	}
+	return nil
+}
diff --git a/object/object_test.go b/object/object_test.go
index 3560236..522770c 100644
--- a/object/object_test.go
+++ b/object/object_test.go
@@ -2,13 +2,14 @@ package object_test
 
 import (
 	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/require"
 
 	"github.com/flipez/rocket-lang/evaluator"
 	"github.com/flipez/rocket-lang/lexer"
 	"github.com/flipez/rocket-lang/object"
 	"github.com/flipez/rocket-lang/parser"
-
-	"testing"
 )
 
 type inputTestCase struct {
@@ -149,3 +150,25 @@ func TestAnyToObject(t *testing.T) {
 		}
 	}
 }
+
+func TestObjectToAny(t *testing.T) {
+	stringObj := object.NewString("a")
+	intObj := object.NewInteger(1)
+	floatObj := object.NewFloat(1.2)
+	testcases := map[object.Object]any{
+		stringObj:   "a",
+		intObj:      int64(1),
+		floatObj:    float64(1.2),
+		object.TRUE: true,
+		object.NewArrayWithObjects(stringObj, intObj, floatObj): []any{"a", int64(1), float64(1.2)},
+		object.NIL: nil,
+	}
+
+	hash := object.NewHash(nil)
+	hash.Set("a", int64(1))
+	testcases[hash] = map[any]any{"a": int64(1)}
+
+	for input, expected := range testcases {
+		require.Equal(t, expected, object.ObjectToAny(input))
+	}
+}
diff --git a/object/string.go b/object/string.go
index 526321c..6eb2376 100644
--- a/object/string.go
+++ b/object/string.go
@@ -71,7 +71,7 @@ func init() {
 🚀 » "test%s".format("test")
 » "testtest"`,
 				ArgPattern: Args(
-					OverloadArg(STRING_OBJ, INTEGER_OBJ, FLOAT_OBJ, BOOLEAN_OBJ),
+					OverloadArg(STRING_OBJ, INTEGER_OBJ, FLOAT_OBJ, BOOLEAN_OBJ, ARRAY_OBJ, HASH_OBJ),
 				),
 				ReturnPattern: Args(
 					Arg(STRING_OBJ),
@@ -79,20 +79,10 @@ func init() {
 			},
 			method: func(o Object, args []Object, _ Environment) Object {
 				s := o.(*String)
-				nativeObjects := []interface{}{}
-				for _, arg := range args {
-					switch e := arg.(type) {
-					case *String:
-						nativeObjects = append(nativeObjects, e.Value)
-					case *Integer:
-						nativeObjects = append(nativeObjects, e.Value)
-					case *Float:
-						nativeObjects = append(nativeObjects, e.Value)
-					case *Boolean:
-						nativeObjects = append(nativeObjects, e.Value)
-					}
+				nativeObjects := make([]any, len(args))
+				for idx, arg := range args {
+					nativeObjects[idx] = ObjectToAny(arg)
 				}
-
 				return NewString(fmt.Sprintf(s.Value, nativeObjects...))
 			},
 		},