Difference between revisions of "String.gsub"

From GiderosMobile
m (formatting)
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__NOTOC__
 
__NOTOC__
 
<languages />
 
 
 
'''<translate>Available since</translate>:''' Gideros 2011.6<br/>
 
'''<translate>Available since</translate>:''' Gideros 2011.6<br/>
 
'''<translate>Class</translate>:''' [[Special:MyLanguage/string|string]]<br/>
 
'''<translate>Class</translate>:''' [[Special:MyLanguage/string|string]]<br/>
  
=== <translate>Description</translate> ===
+
=== Description ===
<translate>
 
 
Returns a copy of s in which all (or the first n, if given) occurrences of the pattern have been replaced by a replacement string specified by repl, which can be a string, a table, or a function. gsub also returns, as its second value, the total number of matches that occurred.
 
Returns a copy of s in which all (or the first n, if given) occurrences of the pattern have been replaced by a replacement string specified by repl, which can be a string, a table, or a function. gsub also returns, as its second value, the total number of matches that occurred.
  
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* If repl is a function, then this function is called every time a match occurs, with all captured substrings passed as arguments, in order; if the pattern specifies no captures, then the whole match is passed as a sole argument.
 
* If repl is a function, then this function is called every time a match occurs, with all captured substrings passed as arguments, in order; if the pattern specifies no captures, then the whole match is passed as a sole argument.
 
* If the value returned by the table query or by the function call is a string or a number, then it is used as the replacement string; otherwise, if it is false or nil, then there is no replacement (that is, the original match is kept in the string).
 
* If the value returned by the table query or by the function call is a string or a number, then it is used as the replacement string; otherwise, if it is false or nil, then there is no replacement (that is, the original match is kept in the string).
 
 
Here are some examples:<br/>
 
''x = string.gsub("hello world", "(%w+)", "%1 %1") --> x="hello hello world world"''<br/>
 
''x = string.gsub("hello world", "%w+", "%0 %0", 1) --> x="hello hello world"''<br/>
 
''x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1") --> x="world hello Lua from"''<br/>
 
''x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv) --> x="home = /home/roberto, user = roberto"''<br/>
 
''x = string.gsub("4%2B5 = $return 4%2B5$", "%$(.-)%$", function (s) return loadstring(s)() end) --> x="4%2B5 = 9"''<br/>
 
''local t = {name="lua", version="5.1"}''<br/>
 
''x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t) --> x="lua-5.1.tar.gz"''<br/>
 
</translate>
 
 
 
 
<source lang="lua">
 
<source lang="lua">
 
(string) = string.gsub(s,pat,repl,n)
 
(string) = string.gsub(s,pat,repl,n)
 
</source>
 
</source>
  
=== <translate>Parameters</translate> ===
+
=== Parameters ===
 
'''s''': (string) <translate>string where to make replacements</translate><br/>
 
'''s''': (string) <translate>string where to make replacements</translate><br/>
 
'''pat''': (string) <translate>pattern what to replace</translate><br/>
 
'''pat''': (string) <translate>pattern what to replace</translate><br/>
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'''n''': (number) <translate>number of replacements</translate> '''optional'''<br/>
 
'''n''': (number) <translate>number of replacements</translate> '''optional'''<br/>
  
=== <translate>Return values</translate> ===
+
=== Return values ===
 
'''<translate>Returns</translate>''' (string) <translate>modified string with replacements</translate><br/>
 
'''<translate>Returns</translate>''' (string) <translate>modified string with replacements</translate><br/>
 +
 +
=== Examples ===
 +
<source lang="lua">
 +
x = string.gsub("hello world", "(%w+)", "%1 %1") -- x="hello hello world world"
 +
x = string.gsub("hello world", "%w+", "%0 %0", 1) -- x="hello hello world"
 +
x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1") -- x="world hello Lua from"
 +
x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv) -- x="home = /home/roberto, user = roberto"
 +
x = string.gsub("4%2B5 = $return 4%2B5$", "%$(.-)%$", function (s) return loadstring(s)() end) -- x="4%2B5 = 9"
 +
local t = {name="lua", version="5.1"}''
 +
x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t) -- x="lua-5.1.tar.gz"
 +
</source>
  
 
{{String}}
 
{{String}}

Revision as of 23:48, 23 August 2020

Available since: Gideros 2011.6
Class: string

Description

Returns a copy of s in which all (or the first n, if given) occurrences of the pattern have been replaced by a replacement string specified by repl, which can be a string, a table, or a function. gsub also returns, as its second value, the total number of matches that occurred.

  • If repl is a string, then its value is used for replacement. The character % works as an escape character: any sequence in repl of the form %n, with n between 1 and 9, stands for the value of the n-th captured substring (see below). The sequence %0 stands for the whole match. The sequence %% stands for a single %.
  • If repl is a table, then the table is queried for every match, using the first capture as the key; if the pattern specifies no captures, then the whole match is used as the key.
  • If repl is a function, then this function is called every time a match occurs, with all captured substrings passed as arguments, in order; if the pattern specifies no captures, then the whole match is passed as a sole argument.
  • If the value returned by the table query or by the function call is a string or a number, then it is used as the replacement string; otherwise, if it is false or nil, then there is no replacement (that is, the original match is kept in the string).
(string) = string.gsub(s,pat,repl,n)

Parameters

s: (string) string where to make replacements
pat: (string) pattern what to replace
repl: (varies) to what to replace
n: (number) number of replacements optional

Return values

Returns (string) modified string with replacements

Examples

x = string.gsub("hello world", "(%w+)", "%1 %1") -- x="hello hello world world"
x = string.gsub("hello world", "%w+", "%0 %0", 1) -- x="hello hello world"
x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1") -- x="world hello Lua from"
x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv) -- x="home = /home/roberto, user = roberto"
x = string.gsub("4%2B5 = $return 4%2B5$", "%$(.-)%$", function (s) return loadstring(s)() end) -- x="4%2B5 = 9"
local t = {name="lua", version="5.1"}''
x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t) -- x="lua-5.1.tar.gz"