我想用JavaScript格式化价格。我想要一个函数,它将浮点作为参数,并返回如下格式的字符串:

"$ 2,500.00"

我该怎么做?


当前回答

我们也可以使用numeraljs

数字的格式可以像货币、百分比、时间,甚至是带有小数位数、千位和缩写的普通数字。您可以始终创建自定义格式。

var string = numeral(1000).format('0,0');
// '1,000'

其他回答

我建议使用Google可视化API中的NumberFormat类。

你可以这样做:

var formatter = new google.visualization.NumberFormat({
    prefix: '$',
    pattern: '#,###,###.##'
});

formatter.formatValue(1000000); // $ 1,000,000

我选择了一些最好的答案,组合并制作了一个通过ESLint的ECMAScript 2015(ES6)函数。

export const formatMoney = (
  amount,
  decimalCount = 2,
  decimal = '.',
  thousands = ',',
  currencySymbol = '$',
) => {
  if (typeof Intl === 'object') {
    return new Intl.NumberFormat('en-AU', {
      style: 'currency',
      currency: 'AUD',
    }).format(amount);
  }
  // Fallback if Intl is not present.
  try {
    const negativeSign = amount < 0 ? '-' : '';
    const amountNumber = Math.abs(Number(amount) || 0).toFixed(decimalCount);
    const i = parseInt(amountNumber, 10).toString();
    const j = i.length > 3 ? i.length % 3 : 0;
    return (
      currencySymbol +
      negativeSign +
      (j ? i.substr(0, j) + thousands : '') +
      i.substr(j).replace(/(\d{3})(?=\d)/g, `$1${thousands}`) +
      (decimalCount
        ? decimal +
          Math.abs(amountNumber - i)
            .toFixed(decimalCount)
            .slice(2)
        : '')
    );
  } catch (e) {
    // eslint-disable-next-line no-console
    console.error(e);
  }
  return amount;
};

另一种方式:

function centsToDollaString(x){
  var cents = x + ""
  while(cents.length < 4){
    cents = "0" + cents;
  }
  var dollars = cents.substr(0,cents.length - 2)
  var decimal = cents.substr(cents.length - 2, 2)
  while(dollars.length % 3 != 0){
    dollars = "0" + dollars;
  }
  str = dollars.replace(/(\d{3})(?=\d)/g, "$1" + ",").replace(/^0*(?=.)/, "");
  return "$" + str + "." + decimal;
}

http://code.google.com/p/javascript-number-formatter/:

短、快、灵活但独立。只有75行,包括MIT许可证信息、空白行和注释。接受标准数字格式,如#、##0.00或带否定的-000.####。接受任何国家/地区格式,如###0,00,#,###.##,#‘###.##或任何类型的非编号符号。接受任意数字分组。#、##、#0.000或#、####0.##均有效。接受任何冗余/防傻瓜格式。##、###、##。#或0#、#00####0#都正常。自动数字舍入。简单的界面,只需提供如下掩码和值:格式(“0.0000”,3.141592)

UPDATE这是我自己开发的应用程序,用于最常见的任务:

var NumUtil = {};

/**
  Petty print 'num' wth exactly 'signif' digits.
  pp(123.45, 2) == "120"
  pp(0.012343, 3) == "0.0123"
  pp(1.2, 3) == "1.20"
*/
NumUtil.pp = function(num, signif) {
    if (typeof(num) !== "number")
        throw 'NumUtil.pp: num is not a number!';
    if (isNaN(num))
        throw 'NumUtil.pp: num is NaN!';
    if (num < 1e-15 || num > 1e15)
        return num;
    var r = Math.log(num)/Math.LN10;
    var dot = Math.floor(r) - (signif-1);
    r = r - Math.floor(r) + (signif-1);
    r = Math.round(Math.exp(r * Math.LN10)).toString();
    if (dot >= 0) {
        for (; dot > 0; dot -= 1)
            r += "0";
        return r;
    } else if (-dot >= r.length) {
        var p = "0.";
        for (; -dot > r.length; dot += 1) {
            p += "0";
        }
        return p+r;
    } else {
        return r.substring(0, r.length + dot) + "." + r.substring(r.length + dot);
    }
}

/** Append leading zeros up to 2 digits. */
NumUtil.align2 = function(v) {
    if (v < 10)
        return "0"+v;
    return ""+v;
}
/** Append leading zeros up to 3 digits. */
NumUtil.align3 = function(v) {
    if (v < 10)
        return "00"+v;
    else if (v < 100)
        return "0"+v;
    return ""+v;
}

NumUtil.integer = {};

/** Round to integer and group by 3 digits. */
NumUtil.integer.pp = function(num) {
    if (typeof(num) !== "number") {
        console.log("%s", new Error().stack);
        throw 'NumUtil.integer.pp: num is not a number!';
    }
    if (isNaN(num))
        throw 'NumUtil.integer.pp: num is NaN!';
    if (num > 1e15)
        return num;
    if (num < 0)
        throw 'Negative num!';
    num = Math.round(num);
    var group = num % 1000;
    var integ = Math.floor(num / 1000);
    if (integ === 0) {
        return group;
    }
    num = NumUtil.align3(group);
    while (true) {
        group = integ % 1000;
        integ = Math.floor(integ / 1000);
        if (integ === 0)
            return group + " " + num;
        num = NumUtil.align3(group) + " " + num;
    }
    return num;
}

NumUtil.currency = {};

/** Round to coins and group by 3 digits. */
NumUtil.currency.pp = function(amount) {
    if (typeof(amount) !== "number")
        throw 'NumUtil.currency.pp: amount is not a number!';
    if (isNaN(amount))
        throw 'NumUtil.currency.pp: amount is NaN!';
    if (amount > 1e15)
        return amount;
    if (amount < 0)
        throw 'Negative amount!';
    if (amount < 1e-2)
        return 0;
    var v = Math.round(amount*100);
    var integ = Math.floor(v / 100);
    var frac = NumUtil.align2(v % 100);
    var group = integ % 1000;
    integ = Math.floor(integ / 1000);
    if (integ === 0) {
        return group + "." + frac;
    }
    amount = NumUtil.align3(group);
    while (true) {
        group = integ % 1000;
        integ = Math.floor(integ / 1000);
        if (integ === 0)
            return group + " " + amount + "." + frac;
        amount = NumUtil.align3(group) + " " + amount;
    }
    return amount;
}

因为每个问题都需要单线解决方案:

Number.prototype.formatCurrency = function() { return this.toFixed(2).toString().split(/[-.]/).reverse().reduceRight(function (t, c, i) { return (i == 2) ? '-' + t : (i == 1) ? t + c.replace(/(\d)(?=(\d{3})+$)/g, '$1,') : t + '.' + c; }, '$'); }

这很容易针对不同的地区进行更改。只需将“$1”更改为“$1.”和“.”转换为“”、“”和。以数字表示。可以通过更改末尾的“$”来更改货币符号。

或者,如果您有ES6,您可以使用默认值声明函数:

Number.prototype.formatCurrency = function(thou = ',', dec = '.', sym = '$') { return this.toFixed(2).toString().split(/[-.]/).reverse().reduceRight(function (t, c, i) { return (i == 2) ? '-' + t : (i == 1) ? t + c.replace(/(\d)(?=(\d{3})+$)/g, '$1' + thou) : t + dec + c; }, sym); }

console.log((4215.57).formatCurrency())
$4,215.57
console.log((4216635.57).formatCurrency('.', ','))
$4.216.635,57
console.log((4216635.57).formatCurrency('.', ',', "\u20AC"))
€4.216.635,57

哦,它也适用于负数:

console.log((-6635.574).formatCurrency('.', ',', "\u20AC"))
-€6.635,57
console.log((-1066.507).formatCurrency())
-$1,066.51

当然,你不必有货币符号:

console.log((1234.586).formatCurrency(',','.',''))
1,234.59
console.log((-7890123.456).formatCurrency(',','.',''))
-7,890,123.46
console.log((1237890.456).formatCurrency('.',',',''))
1.237.890,46