title: Javascript: How to check if a value exists in an object
body: <p>I have an array of object</p>
  
  <pre><code>var arrObj=[
              {"a" : "11", "b":"Test1"},
              {"a" : "22", "b":"Test2"},
              {"a" : "33", "b":"Test1"},
              {"a" : "44", "b":"Test3"}
             ];
  </code></pre>
  
  <p>I want to check if "11" exists in the object. If this exists then it should return the value of key "b" i.e. "Test1".
  The value in key "a" is always unique.</p>