I want to create a multi-level JSON string with JS.

Scenario

3 countries with 5 grandfathers with 3 kids which whom also have 3 kids that have 5 friends.

I get the data from a external JSON file that looks like this.

 {"countries":[
    {
        "name":"USA",

        "grandfathers":[
            {
                "gFName":"Steve",
                "grandfathersKid":[
                    {
                        "gFKName": "Linda",
                        "kid": [{
                            "name": "Steve JR", 
                            "friends": [{
                                "name": "Kriss|John|Martin|Steven"
                            }]
                        }
                        ]
                    }

                ]
            }
        ]
    }
]}

And now I want to store some of the countries with people and their relatives and friends in a a new JSON list that looks exactly as the list made in the external json file. I aim to use this "homemade" list later on in the script.

My initial response for this was

var tree = new Array();

tree = {};


var countries = new Array();

countries[0] = "canada";
countries[1] = "USA";
countries[2] = "Mexico";
countries[0][0] = "Steve"; //Lives in Canada
countries[0][0][0] = "Linda"; //Daughter of Steve
countries[0][0][0][0] = "Steve JR"; // Kid of Linda
countries[0][0][0][0][0] = "Kriss"; //Steves Friend
...


$.each(countries...function(index, value){
      tree[index].country = value;

  $.each(grandfathers...function(key, value){
      tree[index].country[key].grandfather = value;

}

And so on, but this is not giving me the result I want. What am I doing wrong? And a more effective way than to take each of everything?

Third edit...

I want to create a multi-level JSON string with JS.

Scenario

3 countries with 5 grandfathers with 3 kids which whom also have 3 kids that have 5 friends.

I get the data from a external JSON file that looks like this.

 {"countries":[
    {
        "name":"USA",

        "grandfathers":[
            {
                "gFName":"Steve",
                "grandfathersKid":[
                    {
                        "gFKName": "Linda",
                        "kid": [{
                            "name": "Steve JR", 
                            "friends": [{
                                "name": "Kriss|John|Martin|Steven"
                            }]
                        }
                        ]
                    }

                ]
            }
        ]
    }
]}

And now I want to store some of the countries with people and their relatives and friends in a a new JSON list that looks exactly as the list made in the external json file. I aim to use this "homemade" list later on in the script.

My initial response for this was

var tree = new Array();

tree = {};


var countries = new Array();

countries[0] = "canada";
countries[1] = "USA";
countries[2] = "Mexico";
countries[0][0] = "Steve"; //Lives in Canada
countries[0][0][0] = "Linda"; //Daughter of Steve
countries[0][0][0][0] = "Steve JR"; // Kid of Linda
countries[0][0][0][0][0] = "Kriss"; //Steves Friend
...


$.each(countries...function(index, value){
      tree[index].country = value;

  $.each(grandfathers...function(key, value){
      tree[index].country[key].grandfather = value;

}

And so on, but this is not giving me the result I want. What am I doing wrong? And a more effective way than to take each of everything?

Third edit...

• javascript
• json
• multidimensional-array

• 1 var tree = new Array(); tree = {}; can be condensed to var tree = {};. You should provide an example of your input and the output you want. Your problem seems to be to create the appropriate structure, not the JSON (that's simply JSON.stringify(value)). – Felix Kling Commented Mar 2, 2012 at 12:24
• The example doesn't make sense. You are trying to assign values to strings as if they are arrays. What input do you actually have? What JSON output do you actually want? – Quentin Commented Mar 2, 2012 at 12:40
• @Quentin I have edited my answer, I have a JSON Input, – Philip Commented Mar 2, 2012 at 13:31

4 Answers 4

Is this the sort of thing you're trying to do?

var countries = $.map(oldCountries || [], function(country) {
    return {
        name: country.name,
        people: $.map(country.grandfathers || [], function(gpa) {
            return {
                name: gpa.gFName,
                children: $.map(gpa.grandfathersKid || [], function(parent) {
                    return {
                        name: parent.gFKName,
                        children: $.map(parent.kid || [], function(kid) {
                            return {
                                name: kid.name,
                                friends: kid.friends
                            };
                        })
                    };
                })
            };
        })
    };
});

I wasn't sure what to do with the friends node. Should that be normalized into something more useful, or do you want to leave it alone?

This Fiddle demonstrates the technique.

I think we'd need to know more about your requirements. But several thing I see here are:

• You declare tree and initialize it as an Array, then immediately reinitialize it as an
  empty object
• You are not creating the intermediate nodes here, such as tree[index] but just assuming that they exist.
• You are trying to assign the country[key] property of an object, using the dot-property access.

Can you supply the countries structure and the grandfather's structure. And are they nested?

And finally, what would you like for the output format? The code above hints at it, but it's still a little fuzzy.

Edit

So are you trying to achieve a structure something like this?:

var countries = [
  {
     name: "Canada",
     people: [
       {
          name: "Steve",
          children: [
            {
               name: "Linda",
               children: [
                 {
                    name: "Steve, Jr.",
                    friends: [
                      {
                         name: "Kriss"
                      }
                      //, more friends
                    ]
                 }
                 //, more grandchildren
               ]
            }
            //, more parents
          ]
       }
       //, more grandparents
     ]
   }
   //, more countries
 ];

May be this jsfiddle can help you to get started?
And here is an example derived from your code.

Sounds like a homework, so I'll try to point you in the right direction. I think you are confusing objects and arrays. You could use a "country" object and a "person" object. A country object should have an array of person objects, as inhabitants. Person objects can have an array of person objects as descendants. Add a method like "addDescendant", which creates a new person under a person. From There you can build the structure as you like. Here is some pseudo code:

countries = [];
function Country(name){ this.name = name; this.population = [];}
function Person(kids){this.descendants = []; this.addDescendant = function(){...}; 
    //loop from 1 to kids and add descendants as "new Person"
}
person = new Person(3);
country1 = new Country("MyCountry1");
// now add people to country1.population
countries.push(country1);

The final structure should look something like this:

countries = [
    { name: "country 1",
      people: [{ name: "Steve"}, 
               {name: "Clara", descendants: [{name: "Clara's daughter"}, 
                                             {name: "Clara's son"}]
              ]}
    },
    { name: "country 2",
      people: [{}, {} ...]

    }
];