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?
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
乔纳森·M的代码对我来说太复杂了,所以我重写了它,在Firefox v30上获得了30%的速度提升,在Chrome v35上获得了60%的速度提升(http://jsperf.com/number-formating2):
Number.prototype.formatNumber = function(decPlaces, thouSeparator, decSeparator) {
decPlaces = isNaN(decPlaces = Math.abs(decPlaces)) ? 2 : decPlaces;
decSeparator = decSeparator == undefined ? "." : decSeparator;
thouSeparator = thouSeparator == undefined ? "," : thouSeparator;
var n = this.toFixed(decPlaces);
if (decPlaces) {
var i = n.substr(0, n.length - (decPlaces + 1));
var j = decSeparator + n.substr(-decPlaces);
} else {
i = n;
j = '';
}
function reverse(str) {
var sr = '';
for (var l = str.length - 1; l >= 0; l--) {
sr += str.charAt(l);
}
return sr;
}
if (parseInt(i)) {
i = reverse(reverse(i).replace(/(\d{3})(?=\d)/g, "$1" + thouSeparator));
}
return i + j;
};
用法:
var sum = 123456789.5698;
var formatted = '$' + sum.formatNumber(2, ',', '.'); // "$123,456,789.57"
其他回答
+1向Jonathan M提供原始方法。由于这是一个明确的货币格式化程序,我继续在输出中添加了货币符号(默认为“$”),并添加了一个默认逗号作为千位分隔符。如果您实际上不需要货币符号(或千位分隔符),只需使用“”(空字符串)作为它的参数。
Number.prototype.formatMoney = function(decPlaces, thouSeparator, decSeparator, currencySymbol) {
// check the args and supply defaults:
decPlaces = isNaN(decPlaces = Math.abs(decPlaces)) ? 2 : decPlaces;
decSeparator = decSeparator == undefined ? "." : decSeparator;
thouSeparator = thouSeparator == undefined ? "," : thouSeparator;
currencySymbol = currencySymbol == undefined ? "$" : currencySymbol;
var n = this,
sign = n < 0 ? "-" : "",
i = parseInt(n = Math.abs(+n || 0).toFixed(decPlaces)) + "",
j = (j = i.length) > 3 ? j % 3 : 0;
return sign + currencySymbol + (j ? i.substr(0, j) + thouSeparator : "") + i.substr(j).replace(/(\d{3})(?=\d)/g, "$1" + thouSeparator) + (decPlaces ? decSeparator + Math.abs(n - i).toFixed(decPlaces).slice(2) : "");
};
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;
}
javascript数字格式化程序(以前在Google Code)
短、快、灵活但独立。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/万无一失的格式。##、###、##。#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)。在掩码中包含前缀和后缀
(摘自自述)
看看JavaScriptNumber对象,看看它是否可以帮助您。
toLocaleString()将使用位置特定的千位分隔符格式化数字。toFixed()将数字舍入到特定的小数位数。
要同时使用这些值,必须将其类型改回数字,因为它们都输出字符串。
例子:
Number((someNumber).toFixed(1)).toLocaleString()
EDIT
您可以直接使用toLocaleString,而不必重新转换为数字:
someNumber.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
多个数字
如果需要经常以类似的方式格式化数字,可以创建一个特定的对象以供重用。德语(瑞士):
const money = new Intl.NumberFormat('de-CH',
{ style:'currency', currency: 'CHF' });
const percent = new Intl.NumberFormat('de-CH',
{ style:'percent', maximumFractionDigits: 1, signDisplay: "always"});
其可以用作:
money.format(1234.50); // output CHF 1'234.50
percent.format(0.083); // output +8.3%
非常漂亮。
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;
};