/*including negative values*/    
function nFormatter(num) {
      let neg = false;
       if(num < 0){
         num = num * -1;
         neg = true;
       }
       if (num >= 1000000000) {
         if(neg){
           return -1 * (num / 1000000000).toFixed(1).replace(/\.0$/, '') + 'G';  
         }
         return (num / 1000000000).toFixed(1).replace(/\.0$/, '') + 'G';
       }
       if (num >= 1000000) {
         if(neg){
           return -1 * (num / 1000000).toFixed(1).replace(/\.0$/, '') + 'M';  
         }
         return (num / 1000000).toFixed(1).replace(/\.0$/, '') + 'M';
       }
       if (num >= 1000) {
         if(neg){
           return -1 * (num / 1000).toFixed(1).replace(/\.0$/, '') + 'K';  
         }
         return (num / 1000).toFixed(1).replace(/\.0$/, '') + 'K';
       }
       return num;
    }

最多支持数量。MAX_SAFE_INTEGER到Number。MIN_SAFE_INTEGER

function abbreviateThousands(value) { const num = Number(value) const absNum = Math.abs(num) const sign = Math.sign(num) const numLength = Math.round(absNum).toString().length const symbol = ['K', 'M', 'B', 'T', 'Q'] const symbolIndex = Math.floor((numLength - 1) / 3) - 1 const abbrv = symbol[symbolIndex] || symbol[symbol.length - 1] let divisor = 0 if (numLength > 15) divisor = 1e15 else if (numLength > 12) divisor = 1e12 else if (numLength > 9) divisor = 1e9 else if (numLength > 6) divisor = 1e6 else if (numLength > 3) divisor = 1e3 else return num return `${((sign * absNum) / divisor).toFixed(divisor && 1)}${abbrv}` } console.log(abbreviateThousands(234523452345)) // 234.5b (billion) console.log(abbreviateThousands(Number.MIN_SAFE_INTEGER)) // -9.0q (quadrillion)

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 

进一步改进@Yash的回答，支持负数:

function nFormatter(num) {
    isNegative = false
    if (num < 0) {
        isNegative = true
    }
    num = Math.abs(num)
    if (num >= 1000000000) {
        formattedNumber = (num / 1000000000).toFixed(1).replace(/\.0$/, '') + 'G';
    } else if (num >= 1000000) {
        formattedNumber =  (num / 1000000).toFixed(1).replace(/\.0$/, '') + 'M';
    } else  if (num >= 1000) {
        formattedNumber =  (num / 1000).toFixed(1).replace(/\.0$/, '') + 'K';
    } else {
        formattedNumber = num;
    }   
    if(isNegative) { formattedNumber = '-' + formattedNumber }
    return formattedNumber;
}

nFormatter(-120000)
"-120K"
nFormatter(120000)
"120K"

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

这篇文章很旧了，但我不知何故找到了这篇文章。所以添加我的输入数字js是一站式的解决方案现在一天。它提供了大量的方法来帮助格式化数字

http://numeraljs.com/