JSFiddle - React, Tailwind, and code Playground

HTML

<p>Original: <span id="original"></span></p>

<p>Copies:
    
    <ul></ul>
</p>

JavaScript

var my_array = [1,2,3,4,5];

my_array.foo = 'fim';
my_array.bar = 'bum';
    
function prints_assoc(arr)
{
    var str = "[";

    for(var key in arr)
    {
        str += key + ": " + arr[key] + ", ";
    }

    str = str.substr(0, str.length - 2) + "]";

    return str;
}
    
function copy_assoc(arr)
{
    var out = [];

    for(var key in arr)
    {
        if(!arr.hasOwnProperty(key))
        {
            continue;
        }

        out[key] = arr[key];
    }

    return out;
}

// Print the original
$('#original').html(prints_assoc(my_array));

// Make copies
for(var i = 0; i < 10; i++)
{
    (function(i) {
        var copy = copy_assoc(my_array);
        copy.derp = String(Math.random()).substr(2);
    
        $('ul').append($('<li>').html(prints_assoc(copy)));
    }(i));
}