我需要显示一个货币值的格式1K等于一千,或1.1K, 1.2K, 1.9K等,如果它不是一个偶数千,否则如果低于一千,显示正常500,100,250等,使用JavaScript格式化的数字?


当前回答

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)

其他回答

我想出了一个非常编码的高尔夫球,它非常短!

var beautify=n=>((Math.log10(n)/3|0)==0)?n:Number((n/Math.pow(10,(Math.log10(n)/3|0)*3)).toFixed(1))+[“”,“K”,“M”,“B”,“T”,][Math.log10(n)/3|0]; 控制台.log(美化(1000)) 控制台.log(美化(10000000))

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 

如果你喜欢,就把功劳归于韦伦·弗林

这比他处理负数和“。0”的情况。

循环和“如果”情况越少,IMO就越好。

function abbreviateNumber(number) {
    const SI_POSTFIXES = ["", "k", "M", "G", "T", "P", "E"];
    const sign = number < 0 ? '-1' : '';
    const absNumber = Math.abs(number);
    const tier = Math.log10(absNumber) / 3 | 0;
    // if zero, we don't need a prefix
    if(tier == 0) return `${absNumber}`;
    // get postfix and determine scale
    const postfix = SI_POSTFIXES[tier];
    const scale = Math.pow(10, tier * 3);
    // scale the number
    const scaled = absNumber / scale;
    const floored = Math.floor(scaled * 10) / 10;
    // format number and add postfix as suffix
    let str = floored.toFixed(1);
    // remove '.0' case
    str = (/\.0$/.test(str)) ? str.substr(0, str.length - 2) : str;
    return `${sign}${str}${postfix}`;
}

jsFiddle测试用例-> https://jsfiddle.net/qhbrz04o/9/

我认为这是一个解决方案。

var unitlist = ["","K","M","G"]; function formatnumber(number){ let sign = Math.sign(number); let unit = 0; while(Math.abs(number) > 1000) { unit = unit + 1; number = Math.floor(Math.abs(number) / 100)/10; } console.log(sign*Math.abs(number) + unitlist[unit]); } formatnumber(999); formatnumber(1234); formatnumber(12345); formatnumber(123456); formatnumber(1234567); formatnumber(12345678); formatnumber(-999); formatnumber(-1234); formatnumber(-12345); formatnumber(-123456); formatnumber(-1234567); formatnumber(-12345678);

以下是我对韦伦·弗林的回答的看法。这将删除.0并修复当层不是整数时的未定义。

const SI_SYMBOL = ['', 'k', 'M', 'G', 'T', 'P', 'E'];

abbreviateNumber(num) {
    const tier = Math.floor(Math.log10(num) / 3) || 0;
    let result = '' + num;
    // if zero, we don't need a suffix
    if (tier > 0) {
      // get suffix and determine scale
      const suffix = SI_SYMBOL[tier];
      const scale = Math.pow(10, tier * 3);
      // scale the number
      const scaled = num / scale;
      // format number and add suffix
      result = scaled.toFixed(1).replace('.0', '') + suffix;
    }
    return result;
  }