traversing through JSON string to inner levels using recursive function

Question

I have a JSON input which can go to any number of levels.

I'm giving an input sample of

var d=getEntities( {"Categories": 
{
"Facets": 
    [
    {
    "count": 1,
    "entity": "Company",
    "Company": 
            [
            {

            "entity": "Ford Motor Co",

            "Ford_Motor_Co": 
                [
                    {
                    "count": 1,
                    "entity": "Ford"
                    }
                ]
            }
            ]
    },
        {
            "count": 4,
            "entity": "Country",
              "Country": [
                    {

                        "entity": "Germany",
                         "Germany": [
                                {
                                    "count": 1,
                                    "entity": "Germany"
                                }
                          ],
                        "currency": "Euro (EUR)"
                    },
                    {

                         "entity": "Italy",
                        "Italy": [
                                {
                                     "count": 1,
                                     "entity": "Italy"
                                }
                          ],
                        "currency": "Euro (EUR)"
                    },
                    {

                        "entity": "Japan",
                          "Japan": [
                             {
                                    "count": 1,
                                    "entity": "Japan"
                             }
                          ],
                        "currency": "Yen (JPY)"
                    },
                    {

                        "entity": "South Korea",
                          "South_Korea": [
                              {
                                    "count": 1,
                                    "entity": "South Korea"
                                }
                          ],
                      "currency": "Won (KRW)"
                    }
              ]
        },
        {"count": 5,
              "entity": "Persons",
              "Persons": [
                    {
                         "count": 2,
                        "entity": "Dodge"
                    },
                    {
                        "count": 1,
                        "entity": "Dodge Avenger"
                    },
                    {
                        "count": 1,
                        "entity": "Major League"
                    },
                    {
                        "count": 1,
                        "entity": "Sterling Heights"
                    }
              ]
        }
  ]

}});

I want to add the key value "Entity" in all levels to an array using recursion,

I'm able to collect the data from first level using the string

<html>
<head>
<script src="jquery.js" type="text/javascript"></script>
<script type="text/javascript" src="dataDumper.js"></script>


<script type="text/javascript">

var testJSON = {"Categories": 
{
"Facets": 
    [
    {
    "count": 1,
    "entity": "Company",
    "Company": 
            [
            {

            "entity": "Ford Motor Co",

            "Ford_Motor_Co": 
                [
                    {
                    "count": 1,
                    "entity": "Ford"
                    }
                ]
            }
            ]
    },
        {
            "count": 4,
            "entity": "Country",
              "Country": [
                    {

                        "entity": "Germany",
                         "Germany": [
                                {
                                    "count": 1,
                                    "entity": "Germany"
                                }
                          ],
                        "currency": "Euro (EUR)"
                    },
                    {

                         "entity": "Italy",
                        "Italy": [
                                {
                                     "count": 1,
                                     "entity": "Italy"
                                }
                          ],
                        "currency": "Euro (EUR)"
                    },
                    {

                        "entity": "Japan",
                          "Japan": [
                             {
                                    "count": 1,
                                    "entity": "Japan"
                             }
                          ],
                        "currency": "Yen (JPY)"
                    },
                    {

                        "entity": "South Korea",
                          "South_Korea": [
                              {
                                    "count": 1,
                                    "entity": "South Korea"
                                }
                          ],
                      "currency": "Won (KRW)"
                    }
              ]
        },
        {"count": 5,
              "entity": "Persons",
              "Persons": [
                    {
                         "count": 2,
                        "entity": "Dodge"
                    },
                    {
                        "count": 1,
                        "entity": "Dodge Avenger"
                    },
                    {
                        "count": 1,
                        "entity": "Major League"
                    },
                    {
                        "count": 1,
                        "entity": "Sterling Heights"
                    }
              ]
        }
  ]

}};

function scan(obj)
{
    var k;
    if (obj.hasOwnProperty('entity')) {



        for (k in obj){
           if (obj.hasOwnProperty(k)){


                scan( obj[k] );  


            }                
          }
    } 


    else{
        if(k=='entity')
        {
        alert(obj.entity);
   }
    }


};

scan(testJSON);



</script>
</head>

<body>

</body>

</html>

How do I get in to the inner levels for JSON string using recursive functions?

Dont put an else in, put the if and alert before the call to scan
Thumbs up!!! And thanks a lot!!!! Really appreciate all your help..
@ElRonnoco Ive been experimenting with this thing and do u knw hw we cn add entities in different levels in to same array.. ie entities in level 1 goes to one array, level 2 to nxt and so on..
I'm not clear what you mean. You can add any new property to a Json object just by saying eg Main.new=1 will create a property 'new' in object Main. If you want to create a new Json object use {}. To create an array use []. to add a Json object to an array use myarray.push({}). To add an array to an array use myarray.push([])
with out using "key", do you know how to perform the same operation using array...

El Ronnoco · Accepted Answer · 2012-05-06 09:22:37Z

up vote 0 down vote accepted

I have made a jsfiddle which traverses every object,array and value in the JSON like so...

function scan(obj)
{
    var k;
    if (obj instanceof Object) {
        for (k in obj){
            if (obj.hasOwnProperty(k)){
                //recursive call to scan property
                scan( obj[k] );  
            }                
        }
    } else {
        //not an Object so obj[k] here is a value
    };

};

I get no recursion error (in Chrome). Can you use this to do what you want?

If you need to test if an object is an array use if (obj instanceof Array)

To test if an object has an "entity" property use if (obj.hasOwnProperty('entity'))

To add (or modify an existing) "entity" property use obj.entity = value or obj['entity'] = value

edited May 6 at 9:22

answered May 5 at 8:18

El Ronnoco
4,208721

I've answered this on my iPhone so if someone could fix my formatting i'd be very grateful!!! – El Ronnoco May 5 at 8:22

its showing the error,if is nt defined for If (h.hasOwnProperty(k)) – user1371896 May 5 at 8:24

Ah you may new to test for 'if (h instanceof object)' before entering the loop. – El Ronnoco May 5 at 8:30

no,,,it ws the format of ur code...I was in big letter.. It now alerts first entity Company and then shows "too much recursion " for getEntities(h[k]); – user1371896 May 5 at 8:32

1

The "stop expression" is the one I used in my answer: if ( ({}).toString.apply( prop ) === '[object Object]' ) {. Btw, Object.keys returns an array of the enumerable properties, so it is not needed to use hasOwnProperty. – Florian Margaine May 5 at 9:09

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Florian Margaine · Answer 2 · 2012-05-05 08:04:24Z

up vote 0 down vote

(function recur( obj ) {
    Object.keys( obj ).forEach( function( prop ) {
        // Check if the property is an object
        if ( ({}).toString.apply( prop ) === '[object Object]' ) {
            // If it is, recall this function
            recur( prop );
        }
    } );
} () );

I haven't added your logic, but you get the idea of how to recursively traverse your object.

edited May 5 at 8:04

answered May 5 at 7:49

Florian Margaine
9,2911733

	lemme give this a try...will give u a feedback aftr that.. – user1371896 May 5 at 7:56
	how do I add the value of subobj here for the above example? – user1371896 May 5 at 7:57
	What? I don't understand your comment. – Florian Margaine May 5 at 7:58
	I didnt get what subobj is.. – user1371896 May 5 at 8:04
	Oops, edited my answer correcly. The `subobj` is the property of the object that is an object, so you can traverse it too. – Florian Margaine May 5 at 8:04

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traversing through JSON string to inner levels using recursive function

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traversing through JSON string to inner levels using recursive function

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