range js

index.js

const range = (start, end, step) => {
    const range = []
    typeof step === 'undefined' && (step = 1)
    if (end < start) step = -step
    while (step > 0 ? end >= start : end <= start) {
        range.push(start)
        start += step
    }
    return range
}

// [1,2,3...]
let days = range(1, 31)

// ["January", "February", "March",...]
let months = range(1, 12).map(v =>
    new Date(1970, v - 1, 1).toLocaleString('en-us', {
        month: 'long'
    })
)

// [2020,2019,2018,...,2010]
let years = range(new Date().getFullYear(), new Date().getFullYear() - 10)