Function 'calculateAverageCountryPopulation' should work for an empty array-CodePudding

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const populations = [42000000, 9500000, 3500000, 8400000];

How can i fix this?

function calculateAverageCountryPopulation(populations) {
  const initialValue = 0;
  const sum =
    populations.reduce((a, b) => a   b, initialValue) / populations.length;
  return sum;
}

console.log(calculateAverageCountryPopulation(populations));

CodePudding user response：

Try this !

const populations = [42000000, 9500000, 3500000, 8400000];

function calculateAverageCountryPopulation(populations) {
  const initialValue = 0;
  return populations.length>0 ? populations.reduce((a, b) => a   b, initialValue) / populations.length:0
};

console.log(calculateAverageCountryPopulation(populations));

CodePudding user response：

You could simply check if the array contains any elements

function calculateAverageCountryPopulation(populations) {
  if (!populations.length) {
    return 0;
  }

  const sum = populations.reduce((total, population) => total   population, 0);
  const average = sum / populations.length;

  return average;
}