function   transform(value,args) {
    const suffixes = ['K', 'M', 'B', 'T', 'P', 'E'];

    if (!value) {
      return null;
    }

    if (Number.isNaN(value)) {
      return null;
    }

    if (value < 1000) {
      return value;
    }

    const exp = Math.floor(Math.log(value) / Math.log(1000));

    const returnValue = (value / Math.pow(1000, exp)).toFixed(args) + suffixes[exp - 1];

    return returnValue;
  }

变换(9999 2)

/ /“10.00 k”

这是非常优雅的。

function formatToUnits(number, precision) {
  const abbrev = ['', 'k', 'm', 'b', 't'];
  const unrangifiedOrder = Math.floor(Math.log10(Math.abs(number)) / 3)
  const order = Math.max(0, Math.min(unrangifiedOrder, abbrev.length -1 ))
  const suffix = abbrev[order];

  return (number / Math.pow(10, order * 3)).toFixed(precision) + suffix;
}

formatToUnits(12345, 2)
==> "12.35k"
formatToUnits(0, 3)
==> "0.000"

function AmountConveter(amount) {
  return Math.abs(amount) > 999
    ? Math.sign(amount) * (Math.abs(amount) / 1000).toFixed(1) + "k"
    : Math.sign(amount) * Math.abs(amount);
}

console.log(AmountConveter(1200)); // 1.2k
console.log(AmountConveter(-1200)); // -1.2k
console.log(AmountConveter(900)); // 900
console.log(AmountConveter(-900)); // -900

下面是一个使用for的选项:

函数numberFormat(d) For (var e = 0;D >= 1000;e + +) { D /= 1000; ｝ return d.toFixed(3) + ["， ' k'， ' M'， ' G'][e]; ｝ let s = numberFormat(9012345678); console.log(s == '9.012 G');

通过消除@martin-sznapka解决方案中的循环，您将减少40%的执行时间。

function formatNum(num,digits) {
    let units = ['k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'];
    let floor = Math.floor(Math.abs(num).toString().length / 3);
    let value=+(num / Math.pow(1000, floor))
    return value.toFixed(value > 1?digits:2) + units[floor - 1];

}

速度测试(200000随机样本)从这个线程不同的解决方案

Execution time: formatNum          418  ms
Execution time: kFormatter         438  ms it just use "k" no "M".."T" 
Execution time: beautify           593  ms doesnt support - negatives
Execution time: shortenLargeNumber 682  ms    
Execution time: Intl.NumberFormat  13197ms 

支持负数 检查!isFinite 如果你想要最大单位是M，将' K M G T P E Z Y'改为' K M' 基数选项(1K = 1000 / 1K = 1024)

Number.prototype.prefix = function (precision, base) { var units = ' K M G T P E Z Y'.split(' '); if (typeof precision === 'undefined') { precision = 2; } if (typeof base === 'undefined') { base = 1000; } if (this == 0 || !isFinite(this)) { return this.toFixed(precision) + units[0]; } var power = Math.floor(Math.log(Math.abs(this)) / Math.log(base)); // Make sure not larger than max prefix power = Math.min(power, units.length - 1); return (this / Math.pow(base, power)).toFixed(precision) + units[power]; }; console.log('0 = ' + (0).prefix()) // 0.00 console.log('10000 = ' + (10000).prefix()) // 10.00K console.log('1234000 = ' + (1234000).prefix(1)) // 1.2M console.log('-10000 = ' + (-10240).prefix(1, 1024)) // -10.0K console.log('-Infinity = ' + (-Infinity).prefix()) // -Infinity console.log('NaN = ' + (NaN).prefix()) // NaN