Higher Order Functions – Reduce 

array.reduce((accumulator, currentValue, index, array) => {
  // المنطق
  return updatedAccumulator;
}, initialValue);

const nums = [1, 2, 3, 4, 5];

const sum = nums.reduce((acc, current) => {
  return acc + current;
}, 0);

console.log(sum); // 15

const numbers = [2, 3, 4];

const product = numbers.reduce((acc, current) => acc * current, 1);

console.log(product); // 24

const values = [10, 25, 30, 5];

const max = values.reduce((acc, current) => {
  return current > acc ? current : acc;
}, values[0]);

console.log(max); // 30

const nums = [1, 2, 3, 4, 5, 6];

const sumEven = nums.reduce((acc, current) => {
  if (current % 2 === 0) {
    return acc + current;
  }
  return acc;
}, 0);

console.log(sumEven); // 12

const letters = ['a', 'b', 'c', 'd'];

const joined = letters.reduce((acc, curr) => acc + '-' + curr);

console.log(joined); // a-b-c-d

const scores = [80, 90, 100];

const average = scores.reduce((acc, curr, index, array) => {
  acc += curr;
  if (index === array.length - 1) {
    return acc / array.length;
  }
  return acc;
}, 0);

console.log(average); // 90

const fruits = ['apple', 'banana', 'apple', 'orange', 'banana', 'apple'];

const count = fruits.reduce((acc, fruit) => {
  acc[fruit] = (acc[fruit] || 0) + 1;
  return acc;
}, {});

console.log(count);
// { apple: 3, banana: 2, orange: 1 }