Regular Expression to validate price

Question

I need a regular expression that validate price in the format like:
0.07 //valid
0.0 //Invalid
20 //valid

All the above Expressions are that which I want to achieve

^\d{0,8}(\.\d{1,4})?$

I use the above Expression which also accepts 0.0 which is invalid in my case. Thank you.

Answer 1

为什么不使用那个RegEx，但是也检查value > 0我认为你也不想要负价 - 其他'数字检查'方法最有可能被认为是有效的

Answer 2

You could use a negative lookahead that asserts that what follows from the start of the line is not zero or times a zero followed by an optional part that matches a dot and only zeroes.

^(?!0*\\.0+$)\\d*(?:\\.\\d+)?$

Explanation

• ^ Assert the start of the line
• (?! Negative lookahead
  • 0*\\.0+$ Match zero or more times a 0 followed by a dot and one or more times a 0 until the end of the string
• ) Close lookahead
• \\d* Match zero or more times a digit
• (?: Non capturing group
  • \\.\\d+ Match a dot followed by one or more digits
• )? Close non capturing group and make it optional
• $ Assert the end of the line

Answer 3

In C#, I would advice to use standard libraries to validate decimal values, like using Decimal.TryParse .

You may then implement something like:

public static bool IsValid(string price) {

    var result = Decimal.TryParse(price, out decimal d);

    if (result && d != 0) {
        return true;
    }

    return false;

}