Lua function
ipairs
Summary
Iterates over a numerically keyed table
Prototype
it, t, 0 = ipairs (t)
Description
Returns an iterator function, the table t, and 0, for use in the generic "for" loop.
for i, v in ipairs (t) do
-- process loop here (i is the key, v is the value)
end -- for
The iterator function, called repeatedly, returns the key and value pairs for each table item, starting at 1, until it finds the first missing integer key. For example, if keys 1 to 8 are present, and key 9 is nil, it will return the first 8 values. This occurs even if key 10 is present.
In other words, you cannot use ipairs to iterate over a table with "holes" in the key ranges.
If the table has non-numeric keys, there are gaps in the key sequence, or keys do not start at 1, then you need to use pairs (instead of ipairs) to access every item in the table.
See Also ...
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 table functions
Lua utilities
Scripting
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)
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)
pairs (Traverse all items 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)
(Help topic: lua=ipairs)
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