整数金额千分位加逗号的

function getNum(num){
    let res='';
    while(num!==0){
        let n = num%1000;
        num-=n;
        num/=1000;
        res=','+n+res;
    }
    return res.slice(1);
}
console.log(getNum(1232222222123))
console.log(getNum(12345678))