How to replace undefined values with empty string in an array object?

Question

Array object:

 var jsonList= {
        "list": [{
            "COLUMN_NAME": "control_master_id",
            "REFERENCED_COLUMN_NAME": "control_master_id",
            "REFERENCED_TABLE_NAME": "tbi_controls_master",
            "TABLE_NAME": "tbi_widget_controls"
        }, {
            "COLUMN_NAME": "authorization_id",
            "REFERENCED_COLUMN_NAME": "authorization_id",
            "REFERENCED_TABLE_NAME": "tbi_authorization_master",
            "TABLE_NAME": "tbi_controls_master"
        }, {
            "COLUMN_NAME": undefined,
            "REFERENCED_COLUMN_NAME": undefined,
            "REFERENCED_TABLE_NAME": undefined,
            "TABLE_NAME": "tbi_widget_controls "
        }]
    }

Expected solution:

var jsonList={
    "list": [{
        "COLUMN_NAME": "control_master_id",
        "REFERENCED_COLUMN_NAME": "control_master_id",
        "REFERENCED_TABLE_NAME": "tbi_controls_master",
        "TABLE_NAME": "tbi_widget_controls"
    }, {
        "COLUMN_NAME": "authorization_id",
        "REFERENCED_COLUMN_NAME": "authorization_id",
        "REFERENCED_TABLE_NAME": "tbi_authorization_master",
        "TABLE_NAME": "tbi_controls_master"
    }, {
        "COLUMN_NAME": "",
        "REFERENCED_COLUMN_NAME": "",
        "REFERENCED_TABLE_NAME": "",
        "TABLE_NAME": "tbi_widget_controls "
    }]
}

Is there any solution to do this using underscore.js?Any ideas? Elegant solutions?

Sounds like an X/Y problem. What is producing this? Whatever produced it needs to be fixed — mplungjan
– mplungjan, Commented Jan 16, 2016 at 7:32

Shrinivas Pai · Accepted Answer · 2016-01-16 10:24:42Z

9

You can use this

var updatedList = JSON.stringify(jsonList.list, function (key, value) {return (value === undefined) ? "" : value});

Demo Link Here

answered Jan 16, 2016 at 10:24

Shrinivas Pai

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1 Comment

Gruff Bunny Over a year ago

Woth noting that JSON.stringify returns a string and not an object. You would need to call JSON.parse to convert it back to an object.

Jonathan Warykowski · Accepted Answer · 2016-01-16 15:54:11Z

4

Apologies for the delay, if you don't care about modifying the existing array and its values then this will probably be a lot quicker performance wise. If you can do anything natively using vanilla js then this should always be used over any libraries in my opinion.

jsonList.list.forEach(function(obj) {
  for(var i in obj) { 
    if(obj[i] === undefined) {
      obj[i] = '';
    }
  }
});

You can see the latest version on jsbin here https://jsbin.com/xinuyi/3/edit?html,js,output

answered Jan 16, 2016 at 15:54

Jonathan Warykowski

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Comments

Jonathan Warykowski · Accepted Answer · 2016-01-16 07:53:37Z

2

This is a very quick solution, I haven't benchmarked it but see the solution below or on jsbin: https://jsbin.com/xinuyi/2/edit?html,js,output

var jsonList = {
    "list": [{
        "COLUMN_NAME": "control_master_id",
        "REFERENCED_COLUMN_NAME": "control_master_id",
        "REFERENCED_TABLE_NAME": "tbi_controls_master",
        "TABLE_NAME": "tbi_widget_controls"
    }, {
        "COLUMN_NAME": "authorization_id",
        "REFERENCED_COLUMN_NAME": "authorization_id",
        "REFERENCED_TABLE_NAME": "tbi_authorization_master",
        "TABLE_NAME": "tbi_controls_master"
    }, {
        "COLUMN_NAME": undefined,
        "REFERENCED_COLUMN_NAME": undefined,
        "REFERENCED_TABLE_NAME": undefined,
        "TABLE_NAME": "tbi_widget_controls "
   }]
};

var updatedList = _.map(jsonList.list, function(object, index) {
    return _.mapObject(object, function(val, key) {
        return (val === undefined) ? "" : val;
    });  
});

answered Jan 16, 2016 at 7:53

Jonathan Warykowski

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3 Comments

Jonathan Warykowski Over a year ago

No worries, if you don't care about editing the existing array you could use javascript's native each method which would be faster.

SVK Over a year ago

TypeError: _.mapObject is not a function.. this error im getting after implmenting this logic in my project.

Gruff Bunny Over a year ago

@SVK the function_.mapObject was added in version 1.8.0. You may be using an older version.

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