regex101: PCRE (Legacy) Match Workspace

1st Alternative(?x-i) # FREE-SPACE MODE, case-sensitive (?(DEFINE) (?<ws>[\r\n\t\x20]*) (?<str>"(?:\\[rntbf\\\/] | [[:xdigit:]]{4} | [^\\"[:cntrl:]])*") (?<bool>true|false) (?<nil>nil) (?<num>-?\d+(?:\.\d+)?) (?<elem>(?:(?&str)|(?&bool)|(?&nil)|(?&num))(?&ws)) (?<comma>,(?&ws)) ) # JSON Array \[ (?&ws) (?: (?: (?&elem) | (?R)(?&ws) ) (?(?=(?&comma)(?:(?&elem)|[\[\{]))(?&comma)) )* \]

(?x-i)applies the following effective flags to the remainder of the pattern: gmx

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

i modifier: -insensitive. Case-sensitive match

Comment: FREE-SPACE MODE, case-sensitive

Definition Group(?(DEFINE) (?<ws>[\r\n\t\x20]*) (?<str>"(?:\\[rntbf\\\/] | [[:xdigit:]]{4} | [^\\"[:cntrl:]])*") (?<bool>true|false) (?<nil>nil) (?<num>-?\d+(?:\.\d+)?) (?<elem>(?:(?&str)|(?&bool)|(?&nil)|(?&num))(?&ws)) (?<comma>,(?&ws)) )

Group ws(?<ws>[\r\n\t\x20]*)

Character Class[\r\n\t\x20]*

*matches any number of characters from the set below:

\ra carriage return (ASCII 13)

\na line-feed (newline) character (ASCII 10)

\ta tab character (ASCII 9)

\x20the literal (20₁₆ / 40₈ / 32₁₀)

Group str(?<str>"(?:\\[rntbf\\\/] | [[:xdigit:]]{4} | [^\\"[:cntrl:]])*")

"the literal " (34₁₀ / 42₈ / 22₁₆)

Non-Capturing Group(?:\\[rntbf\\\/] | [[:xdigit:]]{4} | [^\\"[:cntrl:]])*

*repeats the group contents below any number of times:

1st Alternative\\[rntbf\\\/]

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

Character Class[rntbf\\\/]

rthe literal r (114₁₀ / 162₈ / 72₁₆) (case sensitive)

nthe literal n (110₁₀ / 156₈ / 6E₁₆) (case sensitive)

tthe literal t (116₁₀ / 164₈ / 74₁₆) (case sensitive)

bthe literal b (98₁₀ / 142₈ / 62₁₆) (case sensitive)

fthe literal f (102₁₀ / 146₈ / 66₁₆) (case sensitive)

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

2nd Alternative [[:xdigit:]]{4}

Character Class[[:xdigit:]]{4}

{4}matches exactly 4 characters from the set below:

[:xdigit:]a hexadecimal digit [A-Fa-f0-9]

3rd Alternative [^\\"[:cntrl:]]

Negated Character Class[^\\"[:cntrl:]]

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

[:cntrl:]a control character [\x00-\x1F\x7F]

"the literal " (34₁₀ / 42₈ / 22₁₆)

Group bool(?<bool>true|false)

1st Alternativetrue

truethe literal text true (case sensitive)

2nd Alternativefalse

falsethe literal text false (case sensitive)

Group nil(?<nil>nil)

nilthe literal text nil (case sensitive)

Group num(?<num>-?\d+(?:\.\d+)?)

-?optionally matches the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

Non-Capturing Group(?:\.\d+)?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Group elem(?<elem>(?:(?&str)|(?&bool)|(?&nil)|(?&num))(?&ws))

Non-Capturing Group(?:(?&str)|(?&bool)|(?&nil)|(?&num))

1st Alternative(?&str)

(?&str)calls group str as a subroutine

2nd Alternative(?&bool)

(?&bool)calls group bool as a subroutine

3rd Alternative(?&nil)

(?&nil)calls group nil as a subroutine

4th Alternative(?&num)

(?&num)calls group num as a subroutine

(?&ws)calls group ws as a subroutine

Group comma(?<comma>,(?&ws))

Comment: JSON Array

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

(?&ws)calls group ws as a subroutine

Non-Capturing Group(?: (?: (?&elem) | (?R)(?&ws) ) (?(?=(?&comma)(?:(?&elem)|[\[\{]))(?&comma)) )*

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

2nd Alternative # Or # JSON Object \{ (?&ws) (?: (?&str) (?&ws) : (?&ws) (?: (?&elem) | (?R)(?&ws) ) (?(?=(?&comma)["\[\{])(?&comma)) )* \}

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Search reference

Regular Expression

(?x-i)		# FREE-SPACE MODE, case-sensitive

(?(DEFINE)
	(?<ws>[\r\n\t\x20]*)
	(?<str>"(?:\\[rntbf\\\/] | [[:xdigit:]]{4} | [^\\"[:cntrl:]])*")
	(?<bool>true|false)
	(?<nil>nil)
	(?<num>-?\d+(?:\.\d+)?)
	(?<elem>(?:(?&str)|(?&bool)|(?&nil)|(?&num))(?&ws))
	(?<comma>,(?&ws))
)

# JSON Array
\[ (?&ws)
(?:
	(?:
		(?&elem) | (?R)(?&ws)
	)
	(?(?=(?&comma)(?:(?&elem)|[\[\{]))(?&comma))
)*
\]

|	# Or

# JSON Object
\{ (?&ws)
(?:
	(?&str) (?&ws) 
	: (?&ws)
	(?:
		(?&elem) | (?R)(?&ws)
	)
	(?(?=(?&comma)["\[\{])(?&comma))
)*

\}

Test String
New

{"foo":"bar", "bools":true,
"digits":42,
"objects":{ "cool"   :  "beans"},
"arraystoo":[ 

{"thisworks":"yep"},
	{"thisworkstoo":"uh, huh!!"}
]
}

Regular Expressions 101

Regular Expression

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Regular Expression

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