Question: [![enter image description here](https://i.stack.imgur.com/trUh3.png)](https://i.stack.imgur.com/trUh3.png)I am using `Object.keys` function for get the `length` of the array but after push the data in array it will be show array `length` is undefine [enter image description here](https://i.stack.imgur.com/HAijz.png).

so tell me sir how to fix this ?

```js
$scope.sharedBuyerKeyIdList       = []; 
$scope.countBuyerInAlbum          = 0;
$scope.totalSharedUserCount       = [];
$scope.selectBuyerInAlbum = function(index, isChecked, keyId) {
if(isChecked) {
  if($scope.sharedBuyerKeyIdList.indexOf(keyId)){
      var keyId = keyId;
      var buyerKeyId = keyId.toString();
      $scope.sharedBuyerKeyIdList[buyerKeyId] = keyId;
      $scope.countBuyerInAlbum ++;

      $scope.totalSharedUserCount = Object.keys($scope.sharedBuyerKeyIdList).length;
    }
} else {
    var index  = keyId;
    delete $scope.sharedBuyerKeyIdList[index];
    $scope.countBuyerInAlbum --;
    $scope.totalSharedUserCount = Object.keys($scope.sharedBuyerKeyIdList).length;
  }
}
```

Answer: 
Its very simple. Just do following:

1. Check whether Gecko driver driver is already installed or not in your machine using command - **"webdriver-manager status"**. This will show what has already installed like Selenium Server, IE, Chrome and Gecko drivers and version details on command prompt
2. If you do not find the Gecko in the above list. Run below command to install the Gecko driver - **webdriver-manager update**
3. Once Gecko driver installed, change the browserName:"firefox" in conf.js file and run your test scripts.
The downloads (and source code) for Gecko driver is available here : 

<https://github.com/mozilla/geckodriver/releases>

Instructions for installation are there also. There are compiled binaries available for Windows, Linux and MacOS.