diff --git a/c/main_hosted.c b/c/main_hosted.c
index aacc7c4..2c7a997 100644
--- a/c/main_hosted.c
+++ b/c/main_hosted.c
@@ -1,7 +1,7 @@
 #include <stdlib.h>
 #include <string.h>
-#include <stdio.h>
 
+#include "printf.h"
 #include "frame.h"
 #include "class_resolver.h"
 #include "string.h"
@@ -13,7 +13,7 @@ static struct hash_table_entry * load_from_filenames(const char * filenames[], i
   size_t file_size[length];
 
   for (int i = 0; i < length; i++) {
-    printf("load class: %s\n", filenames[i]);
+    debugf("load class: %s\n", filenames[i]);
     buffers[i] = file_read(filenames[i], &file_size[i]);
   }
 
diff --git a/java/lang/Double.java b/java/lang/Double.java
index c9e8795..f11e42c 100644
--- a/java/lang/Double.java
+++ b/java/lang/Double.java
@@ -1,7 +1,30 @@
 package java.lang;
 
 public class Double {
-    public static String toString(double d) {
-        return "";
+    public static String toString(double f) {
+        long integer = (long)f;
+        double frac = (f - (double)integer) * 10000.0;
+        long fraction = (long)frac;
+
+        byte[] int_s = Long.toString(integer).getBytes();
+        byte[] frac_s = Long.toString(fraction).getBytes();
+        int length = int_s.length + frac_s.length + 1;
+        byte[] buf = new byte[length];
+
+        int ix = 0;
+        for (int i = 0; i < int_s.length; i++) {
+            buf[ix] = int_s[i];
+            ix += 1;
+        }
+
+        buf[ix] = (byte)'.';
+        ix += 1;
+
+        for (int i = 0; i < frac_s.length; i++) {
+            buf[ix] = frac_s[i];
+            ix += 1;
+        }
+
+        return new String(buf);
     }
 }
diff --git a/java/lang/Float.java b/java/lang/Float.java
index a26e9bf..e0a43f6 100644
--- a/java/lang/Float.java
+++ b/java/lang/Float.java
@@ -2,6 +2,29 @@ package java.lang;
 
 public class Float {
     public static String toString(float f) {
-        return "";
+        int integer = (int)f;
+        float frac = (f - (float)integer) * 10000.0f;
+        int fraction = (int)frac;
+
+        byte[] int_s = Integer.toString(integer).getBytes();
+        byte[] frac_s = Integer.toString(fraction).getBytes();
+        int length = int_s.length + frac_s.length + 1;
+        byte[] buf = new byte[length];
+
+        int ix = 0;
+        for (int i = 0; i < int_s.length; i++) {
+            buf[ix] = int_s[i];
+            ix += 1;
+        }
+
+        buf[ix] = (byte)'.';
+        ix += 1;
+
+        for (int i = 0; i < frac_s.length; i++) {
+            buf[ix] = frac_s[i];
+            ix += 1;
+        }
+
+        return new String(buf);
     }
 }
diff --git a/java/lang/String.java b/java/lang/String.java
index 82b7cd2..3bdcd2f 100644
--- a/java/lang/String.java
+++ b/java/lang/String.java
@@ -23,6 +23,10 @@ public class String {
         return this;
     }
 
+    public int length() {
+        return value.length;
+    }
+
     public static String valueOf(boolean b) {
         return b ? "true" : "false";
     }
diff --git a/p/TestFloatPrint.java b/p/TestFloatPrint.java
new file mode 100644
index 0000000..b59d543
--- /dev/null
+++ b/p/TestFloatPrint.java
@@ -0,0 +1,11 @@
+package p;
+
+class TestFloatPrint {
+    public static void main() {
+        float f = 1234.5678f;
+        System.out.println(f);
+
+        double d = 1234.5678;
+        System.out.println(d);
+    }
+}