我找到了一个避免精度问题的方法:

function badRound (num, precision) {
    const x = 10 ** precision;
    return Math.round(num * x) / x
}
// badRound(1.005, 2) --> 1

function round (num, precision) {
    const x = 10 ** (precision + 1);
    const y = 10 ** precision;
    return Math.round(Math.round(num * x) / 10) / y
}
// round(1.005, 2) --> 1.01

var num = 34.7654;

num = Math.round(num * 10) / 10;

console.log(num); // Logs: 34.8

const solds = 136780000000; 
const number = (solds >= 1000000000 && solds < 1000000000000) ? { divisor: 1000000000, postfix: "B" }: (solds >= 1000000 && solds < 1000000000) ? { divisor: 1000000, postfix: "M" }: (solds >= 1000 && solds < 1000000) ? { divisor: 1000, postfix: "K" }: { divisor: 1, postfix: null }; 
const floor = Math.floor(solds / number.divisor).toLocaleString(); 
const firstDecimalIndex = solds.toLocaleString().charAt(floor.length+1); 
const final =firstDecimalIndex.match("0")? floor + number.postfix: floor + "." + firstDecimalIndex + number.postfix; 
console.log(final);

136780000000 --> 136.7B

1367800 --> 1.3M

1342 --> 1.3K

如果你的源代码是typescript，你可以使用这样的函数:

public static ToFixedRounded(decimalNumber: number, fractionDigits: number): number {
    var rounded = Math.pow(10, fractionDigits);
    return (Math.round(decimalNumber * rounded) / rounded).toFixed(fractionDigits) as unknown as number;
}

数学。整数(num * 10) / 10无效。

例如，1455581777.8-145558160.4会得到1310023617.3999999。

所以只使用num。tofixed (1)

这似乎对我抛出的任何东西都有效:

function round(val, multiplesOf) {
  var s = 1 / multiplesOf;
  var res = Math.ceil(val*s)/s;
  res = res < val ? res + multiplesOf: res;
  var afterZero = multiplesOf.toString().split(".")[1];
  return parseFloat(res.toFixed(afterZero ? afterZero.length : 0));
}

它是四舍五入的，所以您可能需要根据用例修改它。这应该可以工作:

console.log(round(10.01, 1)); //outputs 11
console.log(round(10.01, 0.1)); //outputs 10.1