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
/
Field<([a-zA-Z]+)>\("([a-zA-Z]+)", null, nullable: true, null\);
/
gm
Field<
matches the characters Field< literally (case sensitive)
1st Capturing Group
([a-zA-Z]+)
Match a single character present in the list below
[a-zA-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 97) and z (index 122) (case sensitive)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
> matches the character > with index 6210 (3E16 or 768) literally (case sensitive)
\( matches the character ( with index 4010 (2816 or 508) literally (case sensitive)
" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
2nd Capturing Group
([a-zA-Z]+)
Match a single character present in the list below
[a-zA-Z]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
", null, nullable: true, null
matches the characters ", null, nullable: true, null literally (case sensitive)
\) matches the character ) with index 4110 (2916 or 518) literally (case sensitive)
; matches the character ; with index 5910 (3B16 or 738) literally (case sensitive)
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

Substitution

Processing...