Merge Objects

mergeobjects.js

function merge(mainObject) {
  for (var i = 1; i < arguments.length; i++) {
    for (var key in arguments[i]){
      mainObject[key] = arguments[i][key];
    }
  }
  
  return mainObject
}

// Make sure each key is unique
var contact = merge({name: 'John'}, {city: 'Brooklyn'}, {State: 'New York'});