[프로그래머스/JS] 짝수 홀수 개수

Problem Description

정수가 담긴 리스트 num_list가 주어질 때, num_list의 원소 중 짝수와 홀수의 개수를 담은 배열을 return 하도록 solution 함수를 완성해보세요.

 

Restrictions

• 1 ≤ num_list의 길이 ≤ 100
• 0 ≤ num_list의 원소 ≤ 1,000

 

Input/Output Example

• 입출력 예 #1 [1, 2, 3, 4, 5]에는 짝수가 2, 4로 두 개, 홀수가 1, 3, 5로 세 개 있습니다.
• 입출력 예 #2 [1, 3, 5, 7]에는 짝수가 없고 홀수가 네 개 있습니다.

 

My solution

function solution(num_list) {
    let result = []
    const even = num_list.filter((x) => x%2 == 0);
    const odd = num_list.filter((x) => x%2 !== 0);
    result.push(even.length)
    result.push(odd.length)
    return result
}

 

Another solutions

function solution(num_list) {
  return [
    num_list.filter((num) => num % 2 === 0).length,
    num_list.filter((num) => num % 2 === 1).length,
  ];
}

function solution(num_list) {
    var answer = [0,0];

    for(let a of num_list){
        answer[a%2] += 1
    }

    return answer;
}

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https://school.programmers.co.kr/learn/courses/30/lessons/120824

프로그래머스

 
https://developer.mozilla.org/ko/docs/Web/JavaScript/Reference/Statements/for...of

for...of - JavaScript | MDN

https://developer.mozilla.org/ko/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

Array.prototype.filter() - JavaScript | MDN