How to insert array into specific index of array?

Question

I have tried the following but they don't work. I want a result like [[[arr1],[arr2],[arr3]],[[arr4],[arr5],[arr6]]].

array3[counter].push(array2[e+f]);
//Uncaught TypeError: Cannot call method 'push' of undefined 
array3.splice(counter,0,array2[e+f]);
//[Array[2], Array[3], Array[4], Array[4], Array[2], Array[3]]

Here is my source code if it helps: http://jsfiddle.net/yUXPz/

• Benjamin Gruenbaum: array3[counter] is the value at index counter, not an array - hence you can't call .push on it.
• Karoly Horvath: "Uncaught TypeError: Cannot call method 'push' of undefined" -> array3[counter] = undefined -> no value at counter.

Answer 1

If you're trying to add an array to array3 at the specified counter location then use this:

 array3[counter] = [];
 array3[counter].push(array2[e+f]);

Here is the output I got:

[
 [
 [
 7,
 8,
 9
 ]
 ],
 [
 [
 3,
 3,
 3,
 4
 ]
 ]
]

Is that what you're looking to get?

• hexicle: I needed the array to look like this [[[arr1],[arr2],[arr3]],[[arr4],[arr5],[arr6]]] i.e. 3 arrays in every array, because my code was just to help me solve this HackerRank problem: hackerrank.com/challenges/two-arrays., and I needed that array structure for my algorithm.