我想格式化我的数字，总是显示2小数点后，四舍五入适用的地方。
例子:
number display
------ -------
1 1.00
1.341 1.34
1.345 1.35
我一直在用这个:
parseFloat(num).toFixed(2);
但是它把1显示为1，而不是1.00。
当前回答
RegExp -替代方法
在输入时，你有字符串(因为你使用解析)，所以我们可以通过只使用字符串操作和整数计算得到结果
let toFix2 = (n) = > n.replace (d / \(?) -(+)。\ \ \ \ d (d + 1) / (_), s, i、d (r) = {> 让k= (+r[0]>=5)+ +d - (r==5 && s=='-'); 返回s +(+i+(k>99)) + "。"(k +(> 99%) ? ? 9: 00”(k≥0 " k " + k)); }) / /测试 console.log toFix2(“1”)); console.log (toFix2 1.341”()); console.log (toFix2 1.345”()); console.log (toFix2 1.005”());
解释
s is sign, i is integer part, d are first two digits after dot, r are other digits (we use r[0] value to calc rounding) k contains information about last two digits (represented as integer number) if r[0] is >=5 then we add 1 to d - but in case when we have minus number (s=='-') and r is exact equal to 5 then in this case we substract 1 (for compatibility reasons - in same way Math.round works for minus numbers e.g Math.round(-1.5)==-1) after that if last two digits k are greater than 99 then we add one to integer part i
其他回答
将数字转换为字符串，只保留两个小数:
var num = 5.56789;
var n = num.toFixed(2);
n的结果是:
5.57
function currencyFormat (num) {
return "$" + num.toFixed(2).replace(/(\d)(?=(\d{3})+(?!\d))/g, "$1,")
}
console.info(currencyFormat(2665)); // $2,665.00
console.info(currencyFormat(102665)); // $102,665.00
你可以使用numeric .js。
numeral(1.341).format('0.00') // 1.34
numeral(1.345).format('0.00') // 1.35
你可以试试下面的代码:
function FormatNumber(number, numberOfDigits = 2) {
try {
return new Intl.NumberFormat('en-US').format(parseFloat(number).toFixed(numberOfDigits));
} catch (error) {
return 0;
}
}
var test1 = FormatNumber('1000000.4444');
alert(test1); // 1,000,000.44
var test2 = FormatNumber(100000000000.55555555, 4);
alert(test2); // 100,000,000,000.5556
(num + "").replace(/^([0-9]*)(\.[0-9]{1,2})?.*$/,"$1$2")
