항해3주차 자바스크립트 프로그래머스 - 배열 두배 만들기

나의 풀이 // for 문이 조금 헷갈림

function solution(numbers) {
    var answer = [];

    for(let i = 0; i < numbers.length; i++) {
        answer.push(numbers[i] * 2);
    }

    return answer;
}

다른 풀이

function solution(numbers) {
    return numbers.map((num) => num * 2);
}

function solution(numbers) {
    return numbers.reduce((a, b) => [...a, b * 2], []);
}

const solution = (numbers) => numbers.map((number) => number * 2)

function solution(numbers) {
    return numbers.map(i=>i*2);
}

function solution(numbers) {
    const results = [];

    numbers.map((item) => {
        results.push(item*2);
    })

    return results;
}

function solution(numbers) {
    var answer = [];
    numbers.forEach(number => answer.push(2*number))
    return answer;
}

function solution(numbers) {
    var answer = [];
    if(!limit(numbers)){
        throw 'out';
    }
    answer = numbers.map((value) => value * 2);
    return answer;
}

let limit = (num) => {
    let result = true;
    for(let i = 0; i < num.length; i++) {
        if(num[i] < -10000 || num[i] > 10000){
            result = false;
        }
    }
    if(num.length < 1 || num.length > 1000) {
        result = false;
    }

    return result;
}

function solution(numbers) {
    var answer = [];
    return numbers.map(number => number * 2);
}

function solution(numbers) {
    var answer = [];
    numbers.forEach(arg => answer.push(arg*2));
    return answer;
}