Summary
Traverse all items in a table
Prototype
next, t, nil = pairs (t)
Description
Returns the 'next' function, the table t, and nil, for use in a for loop.
t = { "hello", "world" }
for k, v in pairs (t) do
print (k, v) -- k is the key, v is the value
end
Compare to ipairs which only traverses numerically-keyed entries.
Use the pairs function to traverse any table. The table will not necessarily be accessed in alphabetic (or any particular) order.
You must not add additional entries to the table during traversal. Doing so is undefined (that is, the script may crash or loop).
You are permitted to delete items from the table during traversal. In other words, if you find an item you want to delete you may assign nil to it, to delete it.
See Also ...
Lua functions
assert - Asserts that condition is not nil and not false
collectgarbage - Collects garbage
dofile - Executes a Lua file
error - Raises an error message
gcinfo - Returns amount of dynamic memory in use
getfenv - Returns the current environment table
getmetatable - Returns the metatable for the object
ipairs - Iterates over a numerically keyed table
load - Loads a chunk by calling a function repeatedly
loadfile - Loads a Lua file and parses it
loadlib - Loads a DLL (obsolete in Lua 5.1)
loadstring - Compiles a string of Lua code
module - Creates a Lua module
next - Returns next key / value pair in a table
pcall - Calls a function in protected mode
print - Prints its arguments
rawequal - Compares two values for equality without invoking metamethods
rawget - Gets the value of a table item without invoking metamethods
rawset - Sets the value of a table item without invoking metamethods
require - Loads a module
select - Returns items in a list
setfenv - Sets a function's environment
setmetatable - Sets the metatable for a table
tonumber - Converts a string (of the given base) to a number
tostring - Converts its argument to a string
type - Returns the type of a variable
unpack - Unpacks a table into individual items
xpcall - Calls a function with a custom error handler
Topics
Lua base functions
Lua bc (big number) functions
Lua bit manipulation functions
Lua coroutine functions
Lua debug functions
Lua io functions
Lua math functions
Lua os functions
Lua package functions
Lua PCRE regular expression functions
Lua script extensions
Lua string functions
Lua syntax
Lua table functions
Lua utilities
Scripting
Scripting callbacks - plugins
(Help topic: lua=pairs)