## How do you write numbers in regular expressions?

To match any number from 0 to 9 we use \d in regex. It will match any single digit number from 0 to 9. \d means [0-9] or match any number from 0 to 9. Instead of writing 0123456789 the shorthand version is [0-9] where [] is used for character range.

**What is quantifier regular expression?**

Quantifiers specify how many instances of a character, group, or character class must be present in the input for a match to be found.

### How do you write a regular expression in syntax?

Syntax for Regular Expressions. To create a regular expression, you must use specific syntaxâ€”that is, special characters and construction rules. For example, the following is a simple regular expression that matches any 10-digit telephone number, in the pattern nnn-nnn-nnnn: \\d {3}-\\d {3}-\\d {4}.

**What is the difference between-1 and-3 regex?**

-3 Regex match only numbers that are exactly 5 digits long – Javascript -1 Regex to match an exact number of characters in a string -1 Regular expression to match exact 11 digits numbers

## Where can I find information about regular expressions?

For a brief introduction, see .NET Regular Expressions. Each section in this quick reference lists a particular category of characters, operators, and constructs that you can use to define regular expressions. We’ve also provided this information in two formats that you can download and print for easy reference:

**What special characters can be used in regular expressions?**

The following table describes some of the most common special characters for use in regular expressions. These characters are categorized as follows: (caret) Matches the start of the line or string of text that the regular expression is searching. For example, a content rule with a location Subject line and the following regular expression:

0