5个缺失的 JavaScript 数字格式化函数

/** 每三位数字添加一个逗号，方便阅读 **/

function CommaFormatted(amount) {
    var delimiter = ","; // replace comma if desired
    amount = new String(amount);
    var a = amount.split(‘.‘,2)
    var d = a[1];
    var i = parseInt(a[0]);
    if(isNaN(i)) { return ‘‘; }
    var minus = ‘‘;
    if(i < 0) { minus = ‘-‘; }
    i = Math.abs(i);
    var n = new String(i);
    var a = [];
    while(n.length > 3)
    {
        var nn = n.substr(n.length-3);
        a.unshift(nn);
        n = n.substr(0,n.length-3);
    }
    if(n.length > 0) { a.unshift(n); }
    n = a.join(delimiter);
    if(d.length < 1) { amount = n; }
    else { amount = n + ‘.‘ + d; }
    amount = minus + amount;
    return amount;
}
 
/**
*   Usage:  CommaFormatted(12345678);
*   result: 12,345,678
**/

function addCommas(nStr) {
    nStr += ‘‘;
    var x = nStr.split(‘.‘);
    var x1 = x[0];
    var x2 = x.length >; 1 ? ‘.‘ + x[1] : ‘‘;
    var rgx = /(d+)(d{3})/;
     
    while (rgx.test(x1)) {
        x1 = x1.replace(rgx, ‘$1‘ + ‘,‘ + ‘$2‘);
    }
     
    return x1 + x2;
}
 
/**
*   Usage:  addCommas(12345678);
*   result: 12,345,678
**/

/** 这个函数可以添加分隔逗号或者进行四舍五入。 **/

function number_format (number, decimals, dec_point, thousands_sep) {
 
    number = (number + ‘‘).replace(/[^0-9+-Ee.]/g, ‘‘);
    var n = !isFinite(+number) ? 0 : +number,
        prec = !isFinite(+decimals) ? 0 : Math.abs(decimals),
        sep = (typeof thousands_sep === ‘undefined‘) ? ‘,‘ : thousands_sep,
        dec = (typeof dec_point === ‘undefined‘) ? ‘.‘ : dec_point,
        s = ‘‘,
        toFixedFix = function (n, prec) {
            var k = Math.pow(10, prec);
            return ‘‘ + Math.round(n * k) / k;
        };
    // Fix for IE parseFloat(0.55).toFixed(0) = 0;
    s = (prec ? toFixedFix(n, prec) : ‘‘ + Math.round(n)).split(‘.‘);
    if (s[0].length > 3) {
        s[0] = s[0].replace(/B(?=(?:d{3})+(?!d))/g, sep);
    }
    if ((s[1] || ‘‘).length < prec) {
        s[1] = s[1] || ‘‘;
        s[1] += new Array(prec - s[1].length + 1).join(‘0‘);
    }
    return s.join(dec);
}
 
/**
*   Usage:  number_format(123456.789, 2, ‘.‘, ‘,‘);
*   result: 123,456.79
**/

/** 给数字添加"st, nd, rd, th"等序数词。 **/

Number.prototype.toOrdinal = function() {
    var n = this % 100;
    var suffix = [‘th‘, ‘st‘, ‘nd‘, ‘rd‘, ‘th‘];
    var ord = n < 21 ? (n < 4 ? suffix[n] : suffix[0]) : (n % 10 > 4 ? suffix[0] : suffix[n % 10]);
    return this + ord;
}
 
/*
*   Usage:
*   var myNumOld = 23
*   var myNumNew = myNumOld.toOrdinal()
*   Result: 23rd
*/