如何在Javascript中获取subArray的所有子级

Question

So here's my problem:

So this is what my array looks like, I have shown a fragment of it here (from the console window).

It's overall pretty basic right? Except for it's indexing. As you see the first has value "1" and let's say the second has value "4" . As for it's subarrays, these have custom indexes too.

Therefore, the old fashioned:

for(i=0; i<array.length; i++){
  someVar = array[i];
  //do something
}

won't work.

I get the 1 or 4 from iterating through another array, so don't need to get those.

I want to get all subArrays(not the further nested subArrays, only the second level).

So basicly what I want is something like this(is there something like this?):

array[someIndex].children.forEach(
  //do something with **this**
)

To make it more practical for you: So I know that the first array has index 1 . How can I get the values of cat1 and cat2 without knowing it has index 2 (this could also be 6 or 42 for example). In this case, the first array only has one subArray but I would like to make it work for multiple subArrays. (to clarify, select cat1 , cat2 from the second level subarray with, in this case, index 2 )

Thanks in advance, any help is appreciated!

Evoc

Answer 1

Those aren't arrays. You have

[   {   "1": { etc...

which is an array containing an object containing multiple other objects. You can't really use a for(i=...) loop for this, because your keys aren't sequential. You should use a for ... in loop instead:

arr = [{"1":{....}}];

for (i in arr[0]) {
   for (j in arr[0][i]) {
       console.log(arr[0][i][j]['msg']);
   }
}

Answer 2

Use Object.getOwnPropertyNames to get the properties ordered with the integer indices first, from smallest to greatest. Iterate them to get msg1 .

 var array = {"1":{"3":{"5":{"data":"someData","moreData":"someMoreData"},"msg1":"hello world","msg2":"foo equals bar"},"5":{"8":{"data":"someData","moreData":"someMoreData"},"msg1":"world hello","msg2":"bar equals foo"},"your_name":"jimmy","your_msg":"hello world"},"4":{"3":{"5":{"data":"someData","moreData":"someMoreData"},"msg1":"hello world","msg2":"foo equals bar"},"5":{"8":{"data":"someData","moreData":"someMoreData"},"msg1":"world hello","msg2":"bar equals foo"},"your_name":"billy","your_msg":"foo equals bar"}}; for(let key of Object.getOwnPropertyNames(array[1])) { if(Object(array[1][key]) !== array[1][key]) break; console.log('msg1 of "'+key+'": ' + array[1][key].msg1); } console.log('your_msg: ' + array[1].your_msg); 

Answer 3

The example you showed it's an array with only one index, inside of this index there are nested objects, you could iterate them using the property iterator (foreach). You have to go to the second level tho, since the values you need are there.

for (var key in object) {
    for(var anotherKey in object[key]) {
        //check for undefined 
        if(object[key][anotherKey].hasOwnProperty('msg')) {
            //code
        }

    }
}

{ } - declaring objects (literal)

[ ] - declaring arrays