javascript - 如何使用 toLocaleString 格式化大数字？

Question

我需要像这样将非常大的数字格式化为数十亿或数百万:

$ 100.00 B 或 $90.00 M

// this is my code so far:

var currency = doc.stock.exchange.currency; //this is how I get the currency
  var formatNumberNat = val.toLocaleString(
    'en-US', {
      style: 'currency',
      currency: currency
    }
  );
return formatNumberNat; /* €90,102,409,320.00 */

Answer 1

您可以使用像这样的函数来包装 toLocaleString:

const currencyToString = (
  num, {
    locale = "en-US",
    currency = "USD",
    minimumFractionDigits = 2,
    maximumFractionDigits,
    abbreviationFormats
  }
) => {
  if (num == null || typeof num !== "number") {
    // null, undefined, non-numeric, return what was provided
    return num;
  }

  let format;
  if (abbreviationFormats != null) {
    // formats were provided, find one that works
    format = abbreviationFormats.find(f => num >= f.value);
  }

  if (format != null) {
    // apply the format, insert the symbol next to the numeric portion of the formatted string
    const {
      value,
      symbol
    } = format;
    const formatted = (num / value).toLocaleString(locale, {
      style: "currency",
      currency,
      minimumFractionDigits,
      maximumFractionDigits
    });
    const parts = formatted.match(/([\D]*)([\d.,]+)([\D]*)/)
    return `${parts[1]}${parts[2]}${symbol}${parts[3]}`
  }

  // otherwise, use the number as provided
  return num.toLocaleString(locale, {
    style: "currency",
    currency,
    minimumFractionDigits,
    maximumFractionDigits
  });
};

这将接受可用于缩写大数字的可选格式结构:

const formats = [
  { value: 1e12, symbol: "T" },
  { value: 1e9, symbol: "B" },
  { value: 1e6, symbol: "M" },
  { value: 1e3, symbol: "K" }  
];

这是一个codesandbox使用 locale 和 currency 的一些组合进行了大量测试。