const number =1000000;

let str = number.toString();
str.slice()

<!-- let temp=number;
let digit;
let str=‘‘;
let i = 0;
do{
digit=temp%10;
if(i%3==0){
str+=‘,‘+digit;
}else{
str+=digit;
}
temp=temp/10;
console.log(digit,temp);
i++

}while(temp>1);
digit=temp%10;
str+=digit;
console.log(str.split(‘‘).reverse().join())
-->

javascript逗号计数格式的多种转化方法