题解 | #颜色字符串转换#

//利用正则表达式
function rgb2hex(sRGB) {
    if (/.*\d{1,3}.*\d{1,3}.*\d{1,3}.*/g.test(sRGB) == false) {
        return sRGB
    }
    let arr = sRGB.match(/(\d{1,3})/g)
    let r = Number(arr[0]).toString(16)
    let g = Number(arr[1]).toString(16)
    let b = Number(arr[2]).toString(16)
    r = r.length == 1 ? "0" + r : r
    g = g.length == 1 ? "0" + g : g
    b = b.length == 1 ? "0" + b : b
    return "#" + r + g + b
}