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

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;
}

其他回答

数字.原型.固定

此解决方案与每个主要浏览器都兼容:

  const profits = 2489.8237;

  profits.toFixed(3) // Returns 2489.824 (rounds up)
  profits.toFixed(2) // Returns 2489.82
  profits.toFixed(7) // Returns 2489.8237000 (pads the decimals)

您只需添加货币符号(例如“$”+利润.toFixed(2)),即可获得美元金额。

自定义函数

如果需要在每个数字之间使用,则可以使用此函数:

函数格式Money(number,decPlaces,decSep,thouSep){decPlaces=isNaN(decPlaces=数学.abs(decPlaces))?2:decPlaces,decSep=decSep的类型==“未定义”?“.”:12月9日;thouSep=thouSep==“未定义”的类型?“,”:thouSep;var符号=数字<0?"-" : "";var i=字符串(parseInt(number=Math.abs(number(number)||0).toFixed(decPlaces)));变量j=(j=i.length)>3?j%3:0;返回标志+(j?i.substr(0,j)+thouSep:“”)+i.substr(j).replace(/(\decSep{3})(?=\decSep)/g,“$1”+thouSep)+(decPlaces?decSep+Math.abs(数字-i).toFixed(decPlace).slice(2):“”);}document.getElementById(“b”).addEventListener(“单击”,event=>{document.getElementById(“x”).innerText=“结果为:”+formatMoney(document.getElement ById(”d“).value);});<label>插入您的金额:<input id=“d”type=“text”placeholder=“Cash amount”/></label><br/><button id=“b”>获取输出</button><p id=“x”>(按下按钮获取输出)</p>

这样使用:

(123456789.12345).formatMoney(2, ".", ",");

如果你总是使用“.”和',',您可以将它们从方法调用中删除,方法将为您默认它们。

(123456789.12345).formatMoney(2);

如果您的文化中有两个符号翻转(即,欧洲人),并且您希望使用默认值,只需在formatMoney方法中粘贴以下两行:

    d = d == undefined ? "," : d,
    t = t == undefined ? "." : t,

自定义功能(ES6)

如果您可以使用现代ECMAScript语法(即,通过Babel),则可以使用更简单的函数:

函数formatMoney(amount,decimalCount=2,decimal=“.”,千=“,”){尝试{decimalCount=数学.abs(decimalCount);decimalCount=isNaN(decimalCount)?2:小数计数;常量负符号=金额<0?"-" : "";让i=parseInt(amount=Math.abs(Number(amount)||0).toFixed(decimalCount)).toString();设j=(i.length>3)?i.长度%3:0;回来否定符号+(j?i.substr(0,j)+千:“”)+i.substr(j).replace(/(\d{3})(?=\d)/g,“$1”+千)+(decimalCount?decimal+Math.abs(amount-i).toFixed(decimalCount).slice(2):“”);}捕获(e){控制台日志(e)}};document.getElementById(“b”).addEventListener(“单击”,event=>{document.getElementById(“x”).innerText=“结果为:”+formatMoney(document.getElement ById(”d“).value);});<label>插入您的金额:<input id=“d”type=“text”placeholder=“Cash amount”/></label><br/><button id=“b”>获取输出</button><p id=“x”>(按下按钮获取输出)</p>

这是我的。。。

function thousandCommas(num) {
  num = num.toString().split('.');
  var ints = num[0].split('').reverse();
  for (var out=[],len=ints.length,i=0; i < len; i++) {
    if (i > 0 && (i % 3) === 0) out.push(',');
    out.push(ints[i]);
  }
  out = out.reverse() && out.join('');
  if (num.length === 2) out += '.' + num[1];
  return out;
}

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)));">

一个简单的选项,通过先反转字符串和基本正则表达式来正确放置逗号。

String.prototype.reverse = function() {
    return this.split('').reverse().join('');
};

Number.prototype.toCurrency = function( round_decimal /*boolean*/ ) {       
     // format decimal or round to nearest integer
     var n = this.toFixed( round_decimal ? 0 : 2 );

     // convert to a string, add commas every 3 digits from left to right 
     // by reversing string
     return (n + '').reverse().replace( /(\d{3})(?=\d)/g, '$1,' ).reverse();
};

PHP函数“number_format”有一个JavaScript端口。

我发现它非常有用,因为它易于使用,并且对PHP开发人员来说是可识别的。

function number_format (number, decimals, dec_point, thousands_sep) {
    var n = number, prec = decimals;

    var toFixedFix = function (n,prec) {
        var k = Math.pow(10,prec);
        return (Math.round(n*k)/k).toString();
    };

    n = !isFinite(+n) ? 0 : +n;
    prec = !isFinite(+prec) ? 0 : Math.abs(prec);
    var sep = (typeof thousands_sep === 'undefined') ? ',' : thousands_sep;
    var dec = (typeof dec_point === 'undefined') ? '.' : dec_point;

    var s = (prec > 0) ? toFixedFix(n, prec) : toFixedFix(Math.round(n), prec);
    // Fix for Internet Explorer parseFloat(0.55).toFixed(0) = 0;

    var abs = toFixedFix(Math.abs(n), prec);
    var _, i;

    if (abs >= 1000) {
        _ = abs.split(/\D/);
        i = _[0].length % 3 || 3;

        _[0] = s.slice(0,i + (n < 0)) +
               _[0].slice(i).replace(/(\d{3})/g, sep+'$1');
        s = _.join(dec);
    } else {
        s = s.replace('.', dec);
    }

    var decPos = s.indexOf(dec);
    if (prec >= 1 && decPos !== -1 && (s.length-decPos-1) < prec) {
        s += new Array(prec-(s.length-decPos-1)).join(0)+'0';
    }
    else if (prec >= 1 && decPos === -1) {
        s += dec+new Array(prec).join(0)+'0';
    }
    return s;
}

(原文注释栏,包括以下示例和到期信用)

// Formats a number with grouped thousands
//
// version: 906.1806
// discuss at: http://phpjs.org/functions/number_format
// +   original by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
// +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
// +     bugfix by: Michael White (http://getsprink.com)
// +     bugfix by: Benjamin Lupton
// +     bugfix by: Allan Jensen (http://www.winternet.no)
// +    revised by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
// +     bugfix by: Howard Yeend
// +    revised by: Luke Smith (http://lucassmith.name)
// +     bugfix by: Diogo Resende
// +     bugfix by: Rival
// +     input by: Kheang Hok Chin (http://www.distantia.ca/)
// +     improved by: davook
// +     improved by: Brett Zamir (http://brett-zamir.me)
// +     input by: Jay Klehr
// +     improved by: Brett Zamir (http://brett-zamir.me)
// +     input by: Amir Habibi (http://www.residence-mixte.com/)
// +     bugfix by: Brett Zamir (http://brett-zamir.me)
// *     example 1: number_format(1234.56);
// *     returns 1: '1,235'
// *     example 2: number_format(1234.56, 2, ',', ' ');
// *     returns 2: '1 234,56'
// *     example 3: number_format(1234.5678, 2, '.', '');
// *     returns 3: '1234.57'
// *     example 4: number_format(67, 2, ',', '.');
// *     returns 4: '67,00'
// *     example 5: number_format(1000);
// *     returns 5: '1,000'
// *     example 6: number_format(67.311, 2);
// *     returns 6: '67.31'
// *     example 7: number_format(1000.55, 1);
// *     returns 7: '1,000.6'
// *     example 8: number_format(67000, 5, ',', '.');
// *     returns 8: '67.000,00000'
// *     example 9: number_format(0.9, 0);
// *     returns 9: '1'
// *     example 10: number_format('1.20', 2);
// *     returns 10: '1.20'
// *     example 11: number_format('1.20', 4);
// *     returns 11: '1.2000'
// *     example 12: number_format('1.2000', 3);
// *     returns 12: '1.200'