通过数组内对象内的对象属性过滤对象数组

Question

I'm in a nested hell of objects, here. I feel like there's an answer to this, I just can't quite figure out how to phrase what's happening.

So, I get this giant array of objects from a REST return (something like 450+ objects) that comes loaded like this:

results[0] = {  
prop0: "String",  
prop1: "String",  
prop2: bool,  
prop3: Object {  
    prop0: "String"  
}
prop4: "String"  
}

I'm doing this thing, first, where I'm creating an array of objects that contains just the unique strings out of that nested object's property, along with a count of the number of times that string appears within the data set.

I now need, for each unique string, to create an array of objects within the original dataset where results.prop3.prop0 matches the string in the collapsed array. Was that confusing enough?

From this:

Name: "Joe",
Place: state {
state: "New York",
},
Alive: false
}

To this:

New York (120)
Joe - Dead

I've gotten this far, using underscore.js:

for(index in collapsed){  
var details = _.where(results,{state: {state: collapsed[index][0]}});

console.log(details);

}

But I'm clearly an idiot somewhere, because that's just returning an empty array for each thing in my collapsed array.

Sample of collapsed
[{"New York",120},{"Georgia",79},{"Another Place",15}].

I basically want to build a table of data where, underneath each place, I load in the objects where Place matches the state string all the way at the bottom of the nested object.

To jm_____'s point, I'm going to try that.

Answer 1

Here are examples of data manipulation with underscore based on _.reduce() and _.filter()

Getting collapsed array with number of items grouped by states

var collapsed = _.reduce(response, function(memo, item) {
  if ( ! memo[item.Place.state]) {
    memo[item.Place.state] = 0;
  }
  memo[item.Place.state]++;
  return memo;
}, {});

Result: grouped object with states as keys and count as values.

{
  London: 2,
  New York: 4
}

Getting filtered data by state

var filtered = _.filter(response, function(item) {
  return item.Place.state === "New York";
});

Result: array of objects with only state New York

Link to jsbin demo