[regex] RegEx for validating an integer with a maximum length of 10 characters

Could you please point me the appropriate RegEx for validating an integer with a maximum length of 10 characters?

Valid ones include: 1234567890

Don't forget that integers can be negative:

^\s*-?[0-9]{1,10}\s*$

Here's the meaning of each part:

• ^: Match must start at beginning of string
• \s: Any whitespace character
  • *: Occurring zero or more times
• -: The hyphen-minus character, used to denote a negative integer
  • ?: May or may not occur
• [0-9]: Any character whose ASCII code (or Unicode code point) is between '0' and '9'
  • {1,10}: Occurring at least one, but not more than ten times
• \s: Any whitespace character
  • *: Occurring zero or more times
• $: Match must end at end of string

This ignores leading and trailing whitespace and would be more complex if you consider commas acceptable or if you need to count the minus sign as one of the ten allowed characters.

1 to 10:

[0-9]{1,10}

In .NET (and not only, see the comment below) also valid (with a stipulation) this:

\d{1,10}

C#:

var regex = new Regex("^[0-9]{1,10}$", RegexOptions.Compiled);
regex.IsMatch("1"); // true
regex.IsMatch("12"); // true
..
regex.IsMatch("1234567890"); // true
regex.IsMatch(""); // false
regex.IsMatch(" "); // true
regex.IsMatch("a"); // false

P.S. Here's a very useful sandbox.

0123456789 is not a valid integer (usually zeros will be stripped)

I think something like this regexp would be better to use:

^[1-9]([0-9]*)$

(does not support signed numbers)

In most languages i am aware of, the actual regex for validating should be ^[0-9]{1,10}$; otherwise the matcher will also return positive matches if the to be validated number is part of a longer string.