Javascript 货币验证
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2227370/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Currency validation
提问by dev646
Please help with me writing a JavaScript Validationfor currency/money field.
请帮助我为货币/货币字段编写JavaScript 验证。
So please provide any regular expressionsif u have :)
所以请提供任何正则表达式，如果你有 :)
Also, for my region, don't need any currency symbolslike '$' in the field.
此外，对于我所在的地区，字段中不需要任何货币符号，如“$”。
Only decimals are to be included for validation as special chars., along with numbers.
只有小数才能作为特殊字符. 和数字一起包含在验证中。
回答by Andy E
You could use a regexp:
您可以使用正则表达式：
var regex = /^\d+(?:\.\d{0,2})$/;
var numStr = "123.20";
if (regex.test(numStr))
alert("Number is valid");
If you're not looking to be as strict with the decimal places you might find it easier to use the unary (+) operator to cast to a number to check it's validity:
如果您不希望对小数位如此严格，您可能会发现使用一元 ( +) 运算符更容易转换为数字以检查其有效性：
var numStr = "123.20";
var numNum = +numStr; // gives 123.20
If the number string is invalid, it will return NaN(Not a Number), something you can test for easily:
如果数字字符串无效，它将返回NaN(Not a Number)，您可以轻松测试：
var numStr = "ab123c";
var numNum = +numStr;
if (isNaN(numNum))
alert("numNum is not a number");
It will, of course, allow a user to add more decimal places but you can chop any extra off using number.toFixed(2)to round to 2 decimal places. parseFloatis much less strict with input and will pluck the first number it can find out of a string, as long as that string starts with a number, eg. parseFloat("123abc")would yield 123.
当然，它允许用户添加更多的小数位，但您可以使用number.toFixed(2)四舍五入到小数点后两位。 parseFloat对输入的严格程度要低得多，只要该字符串以数字开头，就会从字符串中提取它可以找到的第一个数字，例如。parseFloat("123abc")会屈服123。
回答by Sababado
I built my answer from the accepted answer.
我从接受的答案中构建了我的答案。
var regex = /^[1-9]\d*(((,\d{3}){1})?(\.\d{0,2})?)$/;
var regex = /^[1-9]\d*(((,\d{3}){1})?(\.\d{0,2})?)$/;
^[1-9]The number must start with 1-9\d*The number can then have any number of any digits(...)$look at the next group from the end (...)$(...)?(...)?Look for two groups optionally. The first is for the comma, the second is for the decimal.(,\d{3}){1}Look for one occurance of a comma followed by exactly three digits\.\d{0,2}Look for a decimal followed by zero, one, or two digits.
^[1-9]号码必须以 1-9 开头\d*然后号码可以有任意数量的任意数字(...)$从末尾开始(...)$(...)?(...)?查看下一组可选地查找两组。第一个是逗号，第二个是小数点。(,\d{3}){1}查找逗号后跟三位数字的一次出现\.\d{0,2}查找小数位后跟零、一位或两位数字。
This regex works off of these rules:
此正则表达式适用于以下规则：
- Valid values are numbers 0-9, comma and decimal point.
If a customer enters more than one decimal point or more than one comma, the value is invalid and will not be accepted.
Examples of invalid input values
- 1.2.3
- 1,2,4
- Examples of valid input values
- 1.23
- 1,000
- 3967.
- 23
- 1.2
- 999,999.99
- 有效值为数字 0-9、逗号和小数点。
如果客户输入多于一位小数点或多于一个逗号，则该值无效，将不被接受。
无效输入值的示例
- 1.2.3
- 1,2,4
- 有效输入值的示例
- 1.23
- 1,000
- 3967。
- 23
- 1.2
- 999,999.99
An example can be seen here: http://jsfiddle.net/rat141312/Jpxu6/1/
一个例子可以在这里看到：http: //jsfiddle.net/rat141312/Jpxu6/1/
UPDATE
更新
by changing the [1-9]in the regex to [0-9]any number less than 1can also be validated. Example: 0.42, 007
通过将[1-9]正则表达式中的 更改为[0-9]小于1也可以验证的任何数字。示例：0.42、007
回答by meouw
/[1-9]\d*(?:\.\d{0,2})?/
[1-9] - must start with 1 to 9
\d* - any number of other digits
(?: )? - non capturing optional group
\. - a decimal point
\d{0,2} - 0 to 2 digits
does that work for you? or maybe parseFloat:
那对你有用吗？或者parseFloat：
var float = parseFloat( input );
回答by Jasbeer Rawal
For me its working fine for Indian currency in INR
对我来说，它在 INR 中适用于印度货币
var regex = /^[1-9]{0,2}(,{0,1})(\d{2},)*(\d{3})*(?:\.\d{0,2})$/;
var a = '1,111.11';
regex.test(a);
回答by user8640104
let amount = document.querySelector('#amount'), preAmount = amount.value;
amount.addEventListener('input', function(){
if(isNaN(Number(amount.value))){
amount.value = preAmount;
return;
}
let numberAfterDecimal = amount.value.split(".")[1];
if(numberAfterDecimal && numberAfterDecimal.length > 3){
amount.value = Number(amount.value).toFixed(3);;
}
preAmount = amount.value;
})<input type="text" id="amount">