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
下面是Patrick Desjardins(别名Daok)代码,添加了一些注释和一些小改动:
/*
decimal_sep: character used as decimal separator, it defaults to '.' when omitted
thousands_sep: char used as thousands separator, it defaults to ',' when omitted
*/
Number.prototype.toMoney = function(decimals, decimal_sep, thousands_sep)
{
var n = this,
c = isNaN(decimals) ? 2 : Math.abs(decimals), // If decimal is zero we must take it. It means the user does not want to show any decimal
d = decimal_sep || '.', // If no decimal separator is passed, we use the dot as default decimal separator (we MUST use a decimal separator)
/*
According to [https://stackoverflow.com/questions/411352/how-best-to-determine-if-an-argument-is-not-sent-to-the-javascript-function]
the fastest way to check for not defined parameter is to use typeof value === 'undefined'
rather than doing value === undefined.
*/
t = (typeof thousands_sep === 'undefined') ? ',' : thousands_sep, // If you don't want to use a thousands separator you can pass empty string as thousands_sep value
sign = (n < 0) ? '-' : '',
// Extracting the absolute value of the integer part of the number and converting to string
i = parseInt(n = Math.abs(n).toFixed(c)) + '',
j = ((j = i.length) > 3) ? j % 3 : 0;
return sign + (j ? i.substr(0, j) + t : '') + i.substr(j).replace(/(\d{3})(?=\d)/g, "$1" + t) + (c ? d + Math.abs(n - i).toFixed(c).slice(2) : '');
}
这里有一些测试:
// Some tests (do not forget parenthesis when using negative numbers and number with no decimals)
alert(123456789.67392.toMoney() + '\n' + 123456789.67392.toMoney(3) + '\n' + 123456789.67392.toMoney(0) + '\n' + (123456).toMoney() + '\n' + (123456).toMoney(0) + '\n' + 89.67392.toMoney() + '\n' + (89).toMoney());
// Some tests (do not forget parenthesis when using negative numbers and number with no decimals)
alert((-123456789.67392).toMoney() + '\n' + (-123456789.67392).toMoney(-3));
次要变化包括:
移动了一点Math.abs(小数),只有当不是NaN时才能执行。decimal_sep不能再是空字符串(必须使用某种十进制分隔符)我们使用typeof thousand_sep===“undefined”,如How best to determine if a argument is not send to JavaScript function中所建议的不需要(+n||0),因为这是Number对象
JSFiddle公司
其他回答
主要部分是插入千个分隔符,可以这样做:
<script type="text/javascript">
function ins1000Sep(val) {
val = val.split(".");
val[0] = val[0].split("").reverse().join("");
val[0] = val[0].replace(/(\d{3})/g, "$1,");
val[0] = val[0].split("").reverse().join("");
val[0] = val[0].indexOf(",") == 0 ? val[0].substring(1) : val[0];
return val.join(".");
}
function rem1000Sep(val) {
return val.replace(/,/g, "");
}
function formatNum(val) {
val = Math.round(val*100)/100;
val = ("" + val).indexOf(".") > -1 ? val + "00" : val + ".00";
var dec = val.indexOf(".");
return dec == val.length-3 || dec == 0 ? val : val.substring(0, dec+3);
}
</script>
<button onclick="alert(ins1000Sep(formatNum(12313231)));">
Patrick热门答案的CoffeeScript:
Number::formatMoney = (decimalPlaces, decimalChar, thousandsChar) ->
n = this
c = decimalPlaces
d = decimalChar
t = thousandsChar
c = (if isNaN(c = Math.abs(c)) then 2 else c)
d = (if d is undefined then "." else d)
t = (if t is undefined then "," else t)
s = (if n < 0 then "-" else "")
i = parseInt(n = Math.abs(+n or 0).toFixed(c)) + ""
j = (if (j = i.length) > 3 then j % 3 else 0)
s + (if j then i.substr(0, j) + t else "") + i.substr(j).replace(/(\d{3})(?=\d)/g, "$1" + t) + (if c then d + Math.abs(n - i).toFixed(c).slice(2) else "")
PatrickDesjardins的回答看起来不错,但我更喜欢简单的JavaScript代码。下面是我刚刚编写的一个函数,用于输入一个数字并以货币格式返回(减去美元符号):
// Format numbers to two decimals with commas
function formatDollar(num) {
var p = num.toFixed(2).split(".");
var chars = p[0].split("").reverse();
var newstr = '';
var count = 0;
for (x in chars) {
count++;
if(count%3 == 1 && count != 1) {
newstr = chars[x] + ',' + newstr;
} else {
newstr = chars[x] + newstr;
}
}
return newstr + "." + p[1];
}
Patrick Desjardins(前Daok)的例子对我很有用。如果有人感兴趣,我将其移植到CoffeeScript。
Number.prototype.toMoney = (decimals = 2, decimal_separator = ".", thousands_separator = ",") ->
n = this
c = if isNaN(decimals) then 2 else Math.abs decimals
sign = if n < 0 then "-" else ""
i = parseInt(n = Math.abs(n).toFixed(c)) + ''
j = if (j = i.length) > 3 then j % 3 else 0
x = if j then i.substr(0, j) + thousands_separator else ''
y = i.substr(j).replace(/(\d{3})(?=\d)/g, "$1" + thousands_separator)
z = if c then decimal_separator + Math.abs(n - i).toFixed(c).slice(2) else ''
sign + x + y + z
使用regexp的更快方法:
Number.prototype.toMonetaryString = function() {
var n = this.toFixed(2), m;
//var = this.toFixed(2).replace(/\./, ','); For comma separator
// with a space for thousands separator
while ((m = n.replace(/(\d)(\d\d\d)\b/g, '$1 $2')) != n)
n = m;
return m;
}
String.prototype.fromMonetaryToNumber = function(s) {
return this.replace(/[^\d-]+/g, '')/100;
}