Updated Avoiding pitfalls (markdown)

Avoiding-pitfalls.md

@@ -99,20 +99,19 @@ but the actual result would be:
 
 because the same memory area has been reuse for each iteration.
 
-The solution is to make sure that each string is available in memory by the time `printTo()` is called.
+The simplest solution is to explicitly duplicate the strings in the `JsonBuffer`:
-For instance, one could allocate all strings out of the loop:
 
     JsonArray& array = jsonBuffer.createArray();
-    char buffer[16][3];
     for (int i=0; i<3; i++) {
-        sprintf(buffer[i], "iteration %d", 0);
+        char buffer[16];
-        array.add(buffer[i]);
+        sprintf(buffer, "iteration %d", 0);
+        array.add(jsonBuffer.strlen(buffer));
     }
     array.printTo(Serial);
 
 The same principle applies to key and values of `JsonObject`.
 
-Note: ArduinoJson 5.0 (currently in beta), make copies of `String` values but not `char*`.
+Note: If you use `String` instead of a `const char*`, ArduinoJson calls `JsonBuffer::strdup()` implicitly.
 
 #### 7. Make sure the string isn't read-only