코딩물고기의 IT월드
[자바스크립트] reduce
코딩하는물고기
2020. 8. 24. 16:29
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const numbers = [1, 2, 3, 4, 5];
// reduce 통해서 전체 합 구하기,
// const sum = numbers.reduce(
// (accumulator, current, index, array) => accumulator + current,
// 0
// );
// console.log(sum);
// avg = 평균구하기
const avg = numbers.reduce((accumulator, current, index, array) => {
if (index === array.length - 1) {
return (accumulator + current) / array.length;
}
return accumulator + current;
}, 0);
console.log(avg);
------------------------------------------------------------
const alphabets = ["a", "a", "a", "b", "c", "d"];
const counts = alphabets.reduce((acc, current) => {
if (acc[current]) {
acc[current] += 1;
} else {
acc[current] = 1;
}
return acc;
}, {});
console.log(counts);
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