/**
* 获取数组能拼接处的最小的数
* @params{Array} numbers
* @returns{String|Number}
*/   
function getMinNumber (numbers) {
    if (!numbers || numbers.length === 0) return ''
    return numbers.sort(compare).join('')
}
function compare (a, b) {
    const front = "" + a + b
    const behind = "" + b + a
    return front - behind
}