Difference between revisions of "String.gsub"
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'''Available since:''' Gideros 2011.6<br/> | '''Available since:''' Gideros 2011.6<br/> | ||
=== Description === | === 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| − | Returns a copy of s in which all (or the first n, if given) occurrences of the pattern have been replaced by a replacement string specified by repl, which can be a string, a table, or a function.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. | + | <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Returns a copy of s in which all (or the first n, if given) occurrences of the pattern have been replaced by a replacement string specified by repl, which can be a string, a table, or a function.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. |
| Line 19: | Line 19: | ||
Here are some examples: | Here are some 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"]]] | |
<br/> | <br/> | ||
| − | + | [[[local t = {name="lua", version="5.1"}]]] | |
| − | + | [[[x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t) --> x="lua-5.1.tar.gz"]]]</translate> | |
<source lang="lua"> | <source lang="lua"> | ||
(string) = string.gsub(s,pat,repl,n) | (string) = string.gsub(s,pat,repl,n) | ||
</source> | </source> | ||
=== Parameters === | === Parameters === | ||
| − | '''s''': (string) string where to make replacements <br/> | + | '''s''': (string) <translate>string where to make replacements</translate> <br/> |
| − | '''pat''': (string) pattern what to replace <br/> | + | '''pat''': (string) <translate>pattern what to replace</translate> <br/> |
| − | '''repl''': (varies) to what to replace <br/> | + | '''repl''': (varies) <translate>to what to replace</translate> <br/> |
| − | '''n''': (number) number of replacements '''optional'''<br/> | + | '''n''': (number) <translate>number of replacements</translate> '''optional'''<br/> |
=== Return values === | === Return values === | ||
| − | '''Returns''' (string) modified string with replacements<br/> | + | '''Returns''' (string) <translate>modified string with replacements</translate><br/> |
Revision as of 13:34, 23 August 2018
Available since: Gideros 2011.6
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).
Here are some 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"]]]
(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
