生成一个特定格式随机数

function  getRanDom(){
    let a = [‘a‘, ‘b‘, ‘c‘, ‘d‘, ‘e‘, ‘f‘, ‘g‘, ‘h‘, ‘i‘, ‘j‘],
        s = ‘‘,
        r = parseInt(Math.random() * 100000);
    r = r < 10000 ? (r + ‘0‘) : r;
    r = (r + ‘‘).split(‘‘);
    for(let i = 0; i < r.length; i ++){
        s += r[i] + a[r[i]];
    }
    return s;
}
console.log(getRanDom());   // 4e2c1b7h0a