JavaScript - Filter Nested Arrays

Question

I'm trying to filter an array in javascript, and am struggling when the array is nested.

At the moment, the furthest I've been able to get is filtering a flat array:

var ID = 3

var arr = [{ id : 1, name: "a" }, { id : 2, name: "b" }, { id : 3, name: "c" }]

var result = arr.filter(function( obj ) {return obj.id == ID;});
alert(result[0].name);

Though the above doesn't work if the array looks like this instead:

var arr2 = [
    [{ id : 1, name: "a" },{ id : 2, name: "b" }],
    [{ id : 3, name: "c" },{ id : 4, name: "d" }]
] 

The two examples can be found: https://jsfiddle.net/vjt45xv4/

Any tips for finding the appropriate result on the nested array would be much appreciated.

Thanks!

Answer 1

arr2.filter(function(obj) {

  obj.filter(function(d) { 

    if(d.id == ID) { 

      result = d;

    }

  })

});

alert(result.name);

Hope this is what you were looking for. Rather than flattening the data here I went into the nested array till the point where it was flat(and matching) and set the result there.

arr2.forEach(function(d) {

  d.forEach(

    function(dd){ 

      alert(dd.id);

      if (dd.id==ID){

        result=dd; 

      }

    }

  );

});

alert(result.name);

Edit: As minitech mentioned its same working if just using forEach.

Answer 2

Flatten the array then filter it:

arr.reduce(function(a,b) { return a.concat(b);  })
   .filter(function(obj) { return obj.id == ID; });