Lua table standard library

Documentation for the Lua table standard library.

From Lua 5.1 Reference Manual by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes.

Copyright © 2006-2012 Lua.org, PUC-Rio.

Freely available under the terms of the Lua license.

FUNCTION
table.concat()

concatenates table items together into a string

table.insert()

inserts a new item into a numerically-keyed table

table.maxn()

returns the highest numeric key in the table

table.remove()

removes an item from a numerically-keyed table

table.sort()

Sorts a table

Functions

table.concat()

table.concat(table,[sep],[i],[j])

Given an array where all elements are strings or numbers, returns table[i]..sep..table[i+1] ... sep..table[j]. The default value for sep is the empty string, the default for i is 1, and the default for j is the length of the table. If i is greater than j, returns the empty string.

PARAMETERS

table
[sep]
[i]
[j]

table.insert()

table.insert(table,[pos],value)

Inserts element value at position pos in table, shifting up other elements to open space, if necessary. The default value for pos is n+1, where n is the length of the table , so that a call table.insert(t,x) inserts x at the end of table t.

PARAMETERS

table
[pos]
value

table.maxn()

table.maxn(table)

Returns the largest positive numerical index of the given table, or zero if the table has no positive numerical indices. (To do its job this function does a linear traversal of the whole table.)

PARAMETERS

table

table.remove()

table.remove(table,[pos])

Removes from table the element at position pos, shifting down other elements to close the space, if necessary. Returns the value of the removed element. The default value for pos is n, where n is the length of the table, so that a call table.remove(t) removes the last element of table t.

PARAMETERS

table
[pos]

table.sort()

table.sort(table,[comp])

Sorts table elements in a given order, in-place, from table[1] to table[n], where n is the length of the table. If comp is given, then it must be a function that receives two table elements, and returns true when the first is less than the second (so that not comp(a[i+1],a[i]) will be true after the sort). If comp is not given, then the standard Lua operator < is used instead.

The sort algorithm is not stable; that is, elements considered equal by the given order may have their relative positions changed by the sort.

PARAMETERS

table
[comp]