Using hasOwnProperty dynamically for error 'Cannot read property '...' of undefined'

Question

I am getting the error

Cannot read property 'billingDate' of undefined

installment here is undefined

response.detailsResponse.installment.billingDate

I want to use hasOwnProperty but in a dynamic way, like I pass the path and the object (to check against) to a function, it does the following checks and return true or false.

function checkProperty(path, obj){
    //assuming path = response.detailsResponse.installment.billingDate
    //assuming obj = response [a json/object]

    //check if response.detailsResponse exists
    //then check if response.detailsResponse.installment exists
    //then check if response.detailsResponse.installment.billingDate exists
}

The path length/keys can vary.

The code has to be optimized and generic.

score 0 · Accepted Answer · answered Apr 09 '17 at 07:38

You can rewrite the function in the following way

    function checkProperty(path,obj){
      splittedarr = path.split('.');
      var tempObj = obj;
      for(var i=1; i<splittedarr.length; i++){
        if(typeof tempObj[splittedarr[i]] === 'undefined'){
         return false;
        }else{
         tempObj = tempObj[splittedarr[i]];
        }
      }
      return true;
     }

Starting from index 1 as in accordance to your example it seems like response in response.detailsResponse.installment.billingDate for path is same as the obj passed to the function.

Using hasOwnProperty dynamically for error 'Cannot read property '...' of undefined'

1 Answers1