Question

70

rated 0 times [ 72] [ 2] / answers: 1 / hits: 22678 / 10 Years ago, fri, january 9, 2015, 12:00:00

Let say We have the following json object:

[{a1 : a1Val, a2 : a2Val, a3 : a3Val}, 

 {b1 : b1Val, b2 : b2Val, b3 : b3Val},



 ....



 {z1 : z1Val, z2 : z2Val, z3 : z3Val}]

How can we retrieve from this object array of only X2 key value pairs.

meaning, the following result:

 [ {a2 : a2Val}, {b2 : b2Val}, ... ,{ z2 : z2Val}]

within the best performance.

The key does not have to contains number.

What I need here is a function that will recieve parameter - i
and return an array of all the i-th objects in the original json object

So for example if we look at the above json object
and we invoke the method we 2 the method will return

 [ {a2 : a2Val}, {b2 : b2Val}, ... ,{ z2 : z2Val}]

Hope it's clear enough.

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Location: Morocco

Member since Fri, May 22, 2020

4 Years ago

answered 10 Years ago jerome · Accepted Answer

You could use Array.map here

var arr = oldArr.map(function(obj){

    var key = Object.keys(obj).sort()[1], rtn = {};    

    return rtn[key] = obj[key], rtn;

});

What you're doing is taking the second key and then returning a new Object with that key and value.