格式化数字,整数部分每隔三位加逗号

 NumFormat() {
       
            let num = this.num +"";
            var intPart = Number(num).toFixed(0); //获取整数部分
            var intPartFormat = intPart.toString().replace(/(\d)(?=(?:\d{3})+$)/g, '$1,');
            let  floatPart = '0';
            if(num.indexOf('.') !== -1){
              floatPart = num.split(".")[1];//小数部分
              return intPartFormat+"."+floatPart;
            }
            return intPartFormat;
        }
```