How check object to undefined?

Question

I have had object

dataSourceConfig.transport.read.url

remoteDataSourceConfig: { 
transport: {
        read: {
            url: null, 
        },
    },
},

How to check dataSourceConfig.transport.read.url for undefiend?

Check http://stackoverflow.com/questions/3390396/how-to-check-for-undefined-in-javascript — Ankit, Jun 14 '13 at 05:29

elclanrs · Accepted Answer · 2013-06-14T05:42:37.840

4

If I understand your question crrectly, you have to check all the intermediary objects for existence:

if (dataSourceConfig &&
    dataSourceConfig.transport &&
    dataSourceConfig.transport.read &&
    dataSourceConfig.transport.read.url != null
) {
  // is not null or undefined
}

Otherwise you can do something like this:

function isKeySet(obj, key) {
  var keys = key.split('.');
  return keys.reduce(function(o,k){ return o[k]; }, obj) != null;
}

isKeySet(dataSourceConfig, 'transport.read.url'); // false

edited Jun 14 '13 at 05:42

answered Jun 14 '13 at 05:28

elclanrs

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Are you know maybe there is function in javascript for this? – Mediator Jun 14 '13 at 05:33
I'm pretty sure there's no built-in function but `isKeySet` above should do. – elclanrs Jun 14 '13 at 05:39

How check object to undefined?

1 Answers1