Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8

Function

  • Match
  • Substitution
  • List
  • Unit Tests
/
[A-Z]+[a-z]{1,2}[0-9]*
/
Match a single character present in the list below
[A-Z]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
Match a single character present in the list below
[a-z]
{1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
Match a single character present in the list below
[0-9]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/

Test String