edward_freedom

const sum = arr => arr
  .flatMap(Object.entries)
  .reduce((acc, [ k, v ]) => (
    acc[k] = acc.hasOwnProperty(k) ? acc[k] + v : v,
    acc
  ), {});


const obj = sum(arr);

чем это может быть вызвано?

private static Image PanelToBitmap(Control pnl) {
    var bmp = new Bitmap(pnl.Width, pnl.Height);
    pnl.DrawToBitmap(bmp, new Rectangle(0, 0, bmp.Width, bmp.Height));
    return bmp;
}

const counter = {};

// пройти по массиву, заполняя counter
arr.forEach((el) => counter[el] = (counter[el] || 0) + 1);

{
  555: 1,
  30167380: 2,
  496903611692199: 1,
  245970100361652: 2,
  711023259278888: 2
}

mainArr.reduce((acc, cur) => {
    if (!acc[cur]) acc[cur] = 0;
    acc[cur]++;
    return acc;
}, {})

std::vector<std::vector<int>> my2dArray;
my2dArray.resize(nRows);

for (int i = 0; i <= nRows; ++i)
{
   my2dArray[i].resize(nColumns);
   for (int j = 0; j <= nColumns; ++j)
   {
      my2dArray[i][j] = myElemData(i, j);
   }
}

function fb3cont() {

  b3Cont.classList.remove("__active");
}
document.onclick = function() {
  if (b3Cont.classList.contains("__active")) { fb3cont()};
}

categories.map(category => {
   if (category.id === category_id) return { ...category, products: category.products.map(product => {
      if (product.id === product_id) return { ...product, is_blocked: 0 };
      return product;
   }) };
   return category;
})

using System;

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            var objectBase = new Base("Base");
            var objectDerivative = new Derivative("Derivative", '7');

            var copyBase = objectBase.CreateCopy();
            var copyDerivative = objectDerivative.CreateCopy();

            Console.WriteLine(copyBase);
            Console.WriteLine(copyDerivative);
        }
    }

    public class Base
    {
        private readonly string _text;

        public string Text
        {
            get { return _text; }
        }

        public Base(string text)
        {
            _text = text;
        }

        public virtual Base CreateCopy()
        {
            return new Base(Text);
        }

        public override string ToString()
        {
            return $"{nameof(Text)}: {Text}";
        }
    }

    public class Derivative : Base
    {
        private readonly char _symbol;

        public char Symbol
        {
            get { return _symbol; }
        }

        public Derivative(string text, char symbol)
            : base(text)
        {
            _symbol = symbol;
        }

        public override Base CreateCopy()
        {
            return new Derivative(Text, Symbol);
        }

        public override string ToString()
        {
            return $"{nameof(Text)}: {Text}, {nameof(Symbol)}: {Symbol}";
        }
    }
}

const a3 = document.querySelector('.a3');
const nado = document.querySelector('.nado');

a3.before(nado)

$('.input-range').on('input', function() {
  $(this)
    .closest('.select')
    .find('.slider')
    .css('left', (((this.value / 50) + 1) * 25) + '%');
});

string filter = "";
if (filterCountryPanel.SelectedIndex != 0)
  filter = string.Format("country = '{0}'", filterCountryPanel.SelectedItem.ToString());
if (filterGenrePanel.SelectedIndex != 0)
  filter += (filter == "" ? "" : " and ") + string.Format("genre = '{0}'", filterGenrePanel.SelectedItem.ToString());
(listRadioStation.DataSource as DataTable).DefaultView.RowFilter = filter == ""?null:filter;

document.querySelectorAll('селектор ваших блоков').forEach(n => {
  const val = +n.dataset.val;
  n.classList.toggle('disable', min > val || val > max);
});