Difference between revisions of "Io.lines"
From GiderosMobile
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=== Description === | === Description === | ||
Opens the given file name in read mode and returns an iterator function. Each time the iterator function is called, it returns a new line from the file. | Opens the given file name in read mode and returns an iterator function. Each time the iterator function is called, it returns a new line from the file. | ||
| + | <syntaxhighlight lang="lua"> | ||
| + | (function) = io.lines(filename) | ||
| + | </syntaxhighlight> | ||
The call '''io.lines()''' (with no file name) is equivalent to '''io.input():lines()''' that is, it iterates over the lines of the default input file. In this case it does not close the file when the loop ends. | The call '''io.lines()''' (with no file name) is equivalent to '''io.input():lines()''' that is, it iterates over the lines of the default input file. In this case it does not close the file when the loop ends. | ||
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When the iterator function detects the end of file, it returns nil (to finish the loop) and automatically closes the file. | When the iterator function detects the end of file, it returns nil (to finish the loop) and automatically closes the file. | ||
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=== Example === | === Example === | ||
'''Iterates over all lines of a file''' | '''Iterates over all lines of a file''' | ||
| − | < | + | <syntaxhighlight lang="lua"> |
for line in io.lines(filename) do | for line in io.lines(filename) do | ||
-- body | -- body | ||
end | end | ||
| − | </ | + | </syntaxhighlight> |
{{Io}} | {{Io}} | ||
Latest revision as of 13:43, 19 May 2025
Available since: Gideros 2011.6
Class: io
Description
Opens the given file name in read mode and returns an iterator function. Each time the iterator function is called, it returns a new line from the file.
(function) = io.lines(filename)
The call io.lines() (with no file name) is equivalent to io.input():lines() that is, it iterates over the lines of the default input file. In this case it does not close the file when the loop ends.
When the iterator function detects the end of file, it returns nil (to finish the loop) and automatically closes the file.
Parameters
filename: (string) filename to open optional
Return values
Returns (function) iterator function
Example
Iterates over all lines of a file
for line in io.lines(filename) do
-- body
end
