CODEWITHSUNDEEP
javascriptregexjsonnode.js
Afshin Mehrabani
Afshin Mehrabani

Reputation: 34969

How to search and select an object in JSON

Consider a JSON like this:

[{
    "type": "person",
    "name": "Mike",
    "age": "29"
},
{
    "type": "person",
    "name": "Afshin",
    "age": "21"
},
{
    "type": "something_else",
    "where": "NY"
}]

I want to search in the JSON value with a key (for example type='person') and then select a whole object of matched item in JSON. For example when I search for type='person' I expect this value:

[{
  "type": "person",
  "name": "Mike",
  "age": "29"
},
{
  "type": "person",
  "name": "Afshin",
  "age": "21"
}]

Because it's a really big JSON value, I don't want to do a brute-force search in all nodes, so I think the only way is using Regular Expressions but I don't know how can I write a Regex to match something like above.

I'm using NodeJs for the application.

Upvotes: 0

Views: 172

Answers (4)

cillierscharl
cillierscharl

Reputation: 7117

Plain javascript : 

var results = dataset.filter(function(p) { 
    if(p.type == 'person') 
    return true; 
});

Upvotes: 1

Chandu
Chandu

Reputation: 4561

If the requirement is to scan multiple times through the collection, the following one time construction overhead might be of worth.

Use hashing based on values of type.Convert the current data structure to hash map.

var hashMap ={

};

hashMap['person'] =[{},{}];

Hope this helps you.

Upvotes: 0

Sharad
Sharad

Reputation: 743

Use

$.grep(jsonarrayobj,function(n, i){
   if(n.type==="person")
{}
})

Upvotes: -2

moonwave99
moonwave99

Reputation: 22797

Using underscore.js#where:

var results = _(yourObject).where({ type: 'person' })

If your data set is very very big [e.g. 10k or so], consider filtering / paginating stuff server side.

Upvotes: 2

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