title: Mapping strings to multiple types for json objects?
body: <p>I want to create a map that I can transform into a json object such as</p>
  
  <pre><code>{
     "a": "apple",
     "b": 2
  }
  </code></pre>
  
  <p>but golang specifies that the map be declare with types, so I can have map[string]string or map[string]int.  How do I create a json object like the above?</p>
  
  <p>Note: I won't know what data and/or types I need until runtime or when I need to create the json object.  Therefore I can't just create an object like</p>
  
  <pre><code>type Foo struct {
      A string `json:"a"`
      B int `json:"b"`
  }
  </code></pre>