Question

I need to convert a hash map

{ 
    "fruit" : ["mango","orange"],
    "veg"   : ["carrot"]
} 

to

[ 
  { "type" : "fruit" , "name" : ["mango","orange"] } ,
  { "type" : "veg" ,   "name" : ["carrot"] } 
]

how do I do that??

Answer 1

You can do it like this (in a working snippet):

var input = { 
    "fruit" : ["mango","orange"],
    "veg"   : ["carrot"]
} 

var output = [], item;

for (var type in input) {
    item = {};
    item.type = type;
    item.name = input[type];
    output.push(item);
}

// display result
document.write(JSON.stringify(output));

---

Or, if you or someone else has been extending the Object prototype with enumerable properties (which I think is a bad practice personally), then you could use this to protect from that:

var input = { 
    "fruit" : ["mango","orange"],
    "veg"   : ["carrot"]
} 

var output = [], item;

for (var type in input) {
    if (input.hasOwnProperty(type)) {
        item = {};
        item.type = type;
        item.name = input[type];
        output.push(item);
    }
}

// display result
document.write(JSON.stringify(output));

---

And, using some more modern functionality:

var input = { 
    "fruit" : ["mango","orange"],
    "veg"   : ["carrot"]
};

var output = Object.keys(input).map(function(key) {
   return {type: key, name: input[key]};
});

// display the result
document.write(JSON.stringify(output));