Question

I have a very big Json file (dataset is bigger then 30 000) . I need to check if a part of the value of a certain key is the same as a given string and then increment an int.

This is part of the Json:

[
    {
        "geo": null,
        "coordinates": null,
        "in_reply_to_status_id_str": null,
        "contributors": null,
        "in_reply_to_user_id": null,
        "in_reply_to_status_id": null,
        "truncated": false,
        "created_at": "Tue Nov 13 20:17:17 +0000 2012"

I want to check if the key “created_at” has a certain day(value). Like for example ‘Tue’
and then increment : var tuesday = 0;

only thing i could come up with is this function:

function getValues(obj, key) {
    var objects = [];
    for (var i in obj) {
        if (!obj.hasOwnProperty(i)) continue;
        if (typeof obj[i] == 'object') {
            objects = objects.concat(getValues(obj[i], key));
        } else if (i == key) {
            objects.push(obj[i]);
        }
    }
    return objects;
}

But it only checks the key and puts the value in an array. That is not what i want.

Answer 1

It is not immediately clear from your question what the structure of the data is, but it looks to be an array of objects where the created_at property will be populated with a Date. If you need it to be recursive (which the code you provided suggests) the following code would need modification. But going off the description:

I want to check if the key “created_at” has a certain day(value). Like
for example ‘Tue’ and then increment : var tuesday = 0;

Then the following will take the array as data and result in the variable value containing an object with a map of days and the number of items where the created_at property begins with each of the 7 day of week strings.

var valMap = {
  Sun: 'sunday',
  Mon: 'monday',
  Tue: 'tuesday',
  Wed: 'wednesday',
  Thu: 'thursday',
  Fri: 'friday',
  Sat: 'saturday'
}

var value = data.reduce(function(m, i, x){
  for (d in valMap){
    if (i.created_at.indexOf(d) === 0){
      m[valMap[d]]++;
      return m;
    }
  }
  return m;
}, {
  sunday: 0,
  monday: 0,
  tuesday: 0,
  wednesday: 0,
  thursday: 0,
  friday: 0,
  saturday: 0
});

result would resemble:

{
  sunday: 0,
  monday: 1,
  tuesday: 3,
  wednesday: 0,
  thursday: 1,
  friday: 0,
  saturday: 6
}