Loop through specific indexes in array

Question

I have a table with products and it's variants.

Each one has an index on the table, for instance:

[0] Product 1
[1] Variant 1
[2] Variant 2
[3] Product 2

etc..

I've assigned to an associative array all the variant's indexes along with their value, for instance:

[1] Variant 1 : 13
[2] Variant 2 : 15
[18] Variant 3: 32

Now I want to loop through the table using only the indexes I got on my array.

Is there a way to loop through an element using specific indexes? ( So I don't have to loop through the whole thing and execute what I want whenever it matches ). Something similar to this pseudocode:

loop through my_table on index = [1,2,18]

Edit for Joseph Marikle:

The code part for the array is this:

var variants_index = [];
 $.each($('.variant'),function(){
 variants_index[$(this).index()] = $(this).find('td').eq(1).text();
 });

typing typeof(variants_index) we get: object and typing the var in the console, we get Array and, typing Array.isArray(variants_index) we get true

• user4013295: Just wondering, why don't you use a 2D array?
• Onilol: I'm trying to write my problem as a more simple example.. What I'm actually doing is a little more complex.
• Rory McCrossan: If you're already generating an array containing the indexes you need to find, why not just use that loop to do the work you need?
• Onilol: After trying this approach I might be doing that.. It's a mix of a real question and curiosity.
• Joseph Marikle: @Onilol Thanks. Using typeof against an array will always return "object" in javascript. To test if a variable holds an array, you should use Array.isArray(obj). Your scenario is as I described in my first comment. Both answers below are how I would accomplish what you're trying to do.

Answer 1

You can loop through your array of indices that you are interested in and use their values as an index to your array containing product info.

var indexToCheck = [1,2,18];
for(var i = 0; i < indexToCheck.length; i++){
 var productInfo = myProducts[indexToCheck[i]];
}

Answer 2

loop through my_table on index = [1,2,8] (changed the 18 to 8 for simplicity)

Since that's the core of the problem, let's try to solve it.

index = [1,2,8]
my_table = [5,4,6,7,3,8,2,9,0,1]
for (i=0;i<index.length;i++){
 console.log(my_table[index[i]]);
}

This would get the numbers from "index" as use them as indexes to access positions in my_table