title: Checking if key exist in map which return interface type in go
body: <p>I have a interface and one method.</p>
  
  <p>type IAlertType interface {</p>
  
  <pre><code>CreateAlertDetail(alertId uint, attributes map[string]string,id   uint) IAlertType
  </code></pre>
  
  <p>}</p>
  
  <p>And a map.</p>
  
  <p>var ProductAlertMap = map[string]IAlertType{</p>
  
  <pre><code>"price_ranges": AlertPriceRanges{},
  "rating_ranges" : AlertRatingRanges{},
  "lqi_changes" : AlertLqiChanges{},
  "low_inventories" : AlertLowInventory{},
  </code></pre>
  
  <p>}</p>
  
  <p>I want to check if a string exist in this map or not without knowing the map value?</p>
  
  <p>Ex : String "lqi_changes" exists in this map or not, If exist then return true , if not then false.</p>
  
  <p>Please help me, I am new on Go.</p>