title: merge array using angular 5
body: <p>I have two array:</p>
  
  <p>var obj1 = [{ "a" : "1", "b" : "2" }, { "a" : "3", "b" : "4" }];</p>
  
  <p>var obj2 = [{ "c" : "5", "d" : "6" }, { "c" : "7", "d" : "8" }];</p>
  
  <p>I want final output as:</p>
  
  <p>objFinal: [{ "a" : "1", "b" : "2", "c" : "5", "d" : "6" }, { "a" : "3", "b" : "4", "c" : "7", "d" : "8" }];</p>
  
  <p>I am working on angular 5 with TS</p>