Lua String Library

The string index in--lua is,...... from the back to the next, from the -1,-2 to the front. All function in the--string library does not manipulate the string directly, returning only one result. --------------------------------------------------------------------------------------------------"Basic Functions"

Function	Describe	Example	Results
Len	Calculating string Lengths	String.len ("ABCD")	4
Rep	Returns n copies of a string s	String.rep ("ABCD", 2)	Abcdabcd
Lower	Returns all uppercase letters in a string	String.Lower ("AbcD")	Abcd
Upper	Return string All letters lowercase	String.upper ("AbcD")	Abcd
Format	Returns a formatted string similar to printf	String.Format ("The Value is:%d", 4)	The value Is:4
Sub	Returns substring from index I to J of S	String.sub ("ABCD", 2)	Bcd
String.sub ("ABCD",-2)	Cd
String.sub ("ABCD", 2,-2)	Bc
String.sub ("ABCD", 2, 3)	Bc
Find	Find in string	String.find ("CDCDCDCD", "AB")	Nil
String.find ("CDCDCDCD", "CD")	1 2
String.find ("CDCDCDCD", "CD", 7)	7 8
Gsub	Replace in string	String.gsub ("Abcdabcd", "a", "Z");	ZBCDZBCD 2
String.gsub ("AAAA", "a", "Z", 3);	Zzza 3
Byte	Returns the integer form of the character	String.byte ("ABCD", 4)	68
Char	Converts an integer number to a character and connects	String.char (97,98,99,100)	Abcd

--------------------------------------------------------------------------------------------------"Basic mode string"

Character class	Describe	Example	Results
.	Any character	String.find ("", ".")	Nil
%s	whitespace characters	String.find ("AB CD", "%s%s")	3 4
%s	Non-whitespace characters	String.find ("AB CD", "%S%S")	1 2
%p	Punctuation character	String.find ("Ab,.cd", "%p%p")	3 4
%P	Non-punctuation characters	String.find ("Ab,.cd", "%p%p")	1 2
%c	Control characters	String.find ("abcd\t\n", "%c%c")	5 6
%c	Non-control characters	String.find ("\t\nabcd", "%c%c")	3 4
%d	Digital	String.find ("Abcd12", "%d%d")	5 6
%d	Non-digital	String.find ("12abcd", "%d%d")	3 4
%x	hexadecimal digits	String.find ("Efgh", "%x%x")	1 2
%x	Non-hexadecimal digits	String.find ("Efgh", "%x%x")	3 4
%a	Letters	String.find ("AB12", "%a%a")	1 2
%A	Non-letter	String.find ("AB12", "%a%a")	3 4
%l	lowercase letters	String.find ("ABab", "%l%l")	3 4
%l	Capital	String.find ("ABab", "%l%l")	1 2
%u	Capital	String.find ("ABab", "%u%u")	1 2
%u	Non-capital letters	String.find ("ABab", "%u%u")	3 4
%w	Letters and Numbers	String.find ("A1 ()", "%w%w")	1 2
%W	Non-letter non-numeric	String.find ("A1 ()", "%w%w")	3 4

--------------------------------------------------------------------------------------------------"Escape character%"

Character class	Describe	Example	Results
%	Escape character	String.find ("abc%..", "%")	4 4
String.find ("ABC.. D ","%.%. ")	4 5

--------------------------------------------------------------------------------------------------"Create a character set with []"- "is a hyphen," ^ "represents a complement to a set of characters"

Character class	Describe	Example	Results
[01]	Match binary number	String.find ("32123", "[01]")	3 3
[AB] [CD]	Match AC, AD, BC, BD	String.find ("ABCDEF", "[AB][CD]")	2 3
[[]]	Match an opposing bracket []	String.find ("Abc[]d", "[[]]")	4 5
[1-3]	Match number 1-3	String.find ("312", "[1-3][1-3][1-3]")	1 3
[B-d]	Match Letter B-d	String.find ("DBC", "[b-d][b-d][b-d]")	1 3
[^%s]	Match any non-null character	String.find ("A", "[^%s]")	3 3
[^%d]	Match any non-numeric character	String.find ("123a", "[^%d]")	4 4
[^%a]	Match any non-alphabetic character	String.find ("ABC1", "[^%a]")	4 4

--------------------------------------------------------------------------------------------------"Capture" with "()"

Character class	Describe	Example	Results
()	Capturing strings	String.find ("12ab", "(%a%a)")	3 4 AB
String.find ("Ab12", "(%d%d)")	3 4 12

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