十进制四舍五入
这两段代码帮助你做到四舍五入，对于你显示价格或者订单比较有用：
代码1：
复制代码 代码如下:
function CurrencyFormatted(amount) {
var i = parseFloat(amount);
if(isNaN(i)) { i = 0.00; }
var minus = '';
if(i < 0) { minus = '-'; }
i = Math.abs(i);
i = parseInt((i + .005) * 100);
i = i / 100;
s = new String(i);
if(s.indexOf('.') < 0) { s += '.00'; }
if(s.indexOf('.') == (s.length - 2)) { s += '0'; }
s = minus + s;
return s;
}
/**
* Usage: CurrencyFormatted(12345.678);
* result: 12345.68
**/

代码2：
复制代码 代码如下:
function format_number(pnumber,decimals){
if (isNaN(pnumber)) { return 0};
if (pnumber=='') { return 0};
var snum = new String(pnumber);
var sec = snum.split('.');
var whole = parseFloat(sec[0]);
var result = '';
if(sec.length > 1){
var dec = new String(sec[1]);
dec = String(parseFloat(sec[1])/Math.pow(10,(dec.length - decimals)));
dec = String(whole + Math.round(parseFloat(dec))/Math.pow(10,decimals));
var dot = dec.indexOf('.');
if(dot == -1){
dec += '.';
dot = dec.indexOf('.');
}
while(dec.length <= dot + decimals) { dec += '0'; }
result = dec;
} else{
var dot;
var dec = new String(whole);
dec += '.';
dot = dec.indexOf('.');
while(dec.length <= dot + decimals) { dec += '0'; }
result = dec;
}
return result;
}
/**
* Usage: format_number(12345.678, 2);
* result: 12345.68
**/

添加逗号
这俩段代码帮助你添加逗号到每三位数字中，这让大的数字比较容易查看。
代码1：
复制代码 代码如下:
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
**/

代码2：
复制代码 代码如下:
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
**/

数字格式化，来自PHP
这段javascript代码功能设计来自PHP的nubmer_format功能。能够四舍五入并且加入逗号分隔。而且可以自定义10进制分隔。
复制代码 代码如下:
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
**/

添加一个英文的排序后缀
复制代码 代码如下:
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
*/

除去非数字的字符
复制代码 代码如下:
function stripNonNumeric( str )
{
str += '';
var rgx = /^d|.|-$/;
var out = '';
for( var i = 0; i < str.length; i++ )
{
if( rgx.test( str.charAt(i) ) ){
if( !( ( str.charAt(i) == '.' && out.indexOf( '.' ) != -1 ) ||
( str.charAt(i) == '-' && out.length != 0 ) ) ){
out += str.charAt(i);
}
}
}
return out;
}
/*
* Usage: stripNonNumeric('123et45dhs6.789');
* Result: 123456.789
*/