Regular Expressions 101

Save & Share

  • Save Regex
    ctrl+s
  • Update Regex
    ctrl+⇧+s

Flavor

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

Function

  • Match
  • Substitution
  • List
  • Unit Tests
/
^(?:(?:\+|00)(\d+)[ ]?|(?:\+\+|0))(\d{2})[ ]?(\d{3})[ ]?(\d{2})[ ]?(\d{2})$
/
gm
^ asserts position at start of a line
Non-capturing group
(?:(?:\+|00)(\d+)[ ]?|(?:\+\+|0))
1st Alternative
(?:\+|00)(\d+)[ ]?
Non-capturing group
(?:\+|00)
1st Alternative
\+
\+ matches the character + with index 4310 (2B16 or 538) literally (case sensitive)
2nd Alternative
00
00
matches the characters 00 literally (case sensitive)
1st Capturing Group
(\d+)
\d
matches a digit (equivalent to [0-9])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[ ]
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
matches the character with index 3210 (2016 or 408) literally (case sensitive)
2nd Alternative
(?:\+\+|0)
Non-capturing group
(?:\+\+|0)
1st Alternative
\+\+
\+ matches the character + with index 4310 (2B16 or 538) literally (case sensitive)
\+ matches the character + with index 4310 (2B16 or 538) literally (case sensitive)
2nd Alternative
0
0 matches the character 0 with index 4810 (3016 or 608) literally (case sensitive)
2nd Capturing Group
(\d{2})
\d
matches a digit (equivalent to [0-9])
{2} matches the previous token exactly 2 times
Match a single character present in the list below
[ ]
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
matches the character with index 3210 (2016 or 408) literally (case sensitive)
3rd Capturing Group
(\d{3})
\d
matches a digit (equivalent to [0-9])
{3} matches the previous token exactly 3 times
Match a single character present in the list below
[ ]
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
matches the character with index 3210 (2016 or 408) literally (case sensitive)
4th Capturing Group
(\d{2})
\d
matches a digit (equivalent to [0-9])
{2} matches the previous token exactly 2 times
Match a single character present in the list below
[ ]
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
matches the character with index 3210 (2016 or 408) literally (case sensitive)
5th Capturing Group
(\d{2})
\d
matches a digit (equivalent to [0-9])
{2} matches the previous token exactly 2 times
$ asserts position at the end of a line
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
gm

Test String