get and check javascript array of array

Question

I have a dynamic object which will add new object and update existing array. I need to check below question

1. wheather array has another array?
2. how to get data from array of array ?

below is the array object

[
"Stories",
"Tasks",
"In Progress",
"In Review",
"Completed",
[
    {
        "divName": "content-container2",
        "content": "us 2345",
        "topPos": 109,
        "leftPos": 150
    },
    {
        "divName": "content-container3",
        "content": "Description",
        "topPos": 98,
        "leftPos": 382
    },
    {
        "divName": "content-container4",
        "content": "12212",
        "topPos": 110,
        "leftPos": 644
    }
]
]

Answer 1

I'm addressing what I understood & what I know

I don't know if there are any inbuilt functions are there, you can iterate over array and get your answers.

Ques:- wheather array has another array?

You can use Array.some for this like bellow.

var arr = [1,2,3,[1,2,3],5]
arr.some(function(element){
     return Array.isArray(element)
 })// returns true

it will return true if any element will be array.

Ques:- how to get data from array of array ?

You can use forEach and check that if it is an array access the element

var arr = [1,2,3,[1,2,3],5];
arr.forEach(function(element){
      if(Array.isArray(element)){
         console.log(element[0])
       }
}); //prints 1

If it gives a way to start with it's fine.

NOTE:- Some & ForEach are not supported by IE8. There for loop will work.

Answer 2

As mentioned in the comments you can use isArray method

var arr=/* your array */
var pos=[];
var hasArray=false;
for(var i=0;i<arr.length;i++)
{
   if(Array.isArray(arr[i])){
      hasArray=true;
      pos.push(i);
    }
}
// now getting sub arrays
for(var i=0;i<pos.length;i++)
{
   var subArr=arr[pos[i]];
   /* do something with this subarr */
}

Answer 3

you could loop thru the array, check if the element is array as:

for( var i = 0, len = arr.length; i < len; i++) {
    //check if arr[i] is Array
    if(arr[i] instanceof Array) {
        //its array
        var objArr = arr[i];
        //loop thru all objects
        for(var x = 0, xlen= Object.keys(objArr).length; x < xlen; x++) {
            //loop thru object to get all values
            var obj = objArr[x];
            for(var k in obj) {
                console.log( "Key:"+ k + " value:" + obj[k] );
            }
        }
    }
}

Demo:: jsFiddle