num为传入的数字,n为保留几位小数
fomatFloat(num, n) {
let f = parseFloat(num);
if (isNaN(f)) {
return false;
}
f = Math.round(num * Math.pow(10, n)) / Math.pow(10, n); // n 幂
let s = f.toString();
let rs = s.indexOf('.');
//判定如果是整数，增加小数点再补0
if (rs < 0) {
rs = s.length;
s += '.';
}
while (s.length <= rs + n) {
s += '0';
}
return s;
}
console.log(this.fomatFloat(232.65, 2));//232.65
