3.4.4 – Relational Operators Lua supports the following relational operators: ==: equality ~=: inequality <: less than >: greater than <=: less or equal >=: greater or equal These operators always result in false or true. Equality (==) first compares the type of its operands. If the types are different, then the result is false. Otherwise, the values of the operands are compared. Strings are compared in the obvious way. Numbers are equal if they denote the same mathemat

require (modname) Loads the given module. The function starts by looking into the package.loaded table to determine whether modname is already loaded. If it is, then require returns the value stored at package.loaded[modname]. Otherwise, it tries to find a loader for the module. To find a loader, require is guided by the package.searchers sequence. By changing this sequence, we can change how require looks for a module. The following explanation is based on the default configuration for pac

select (index, ···) If index is a number, returns all arguments after argument number index; a negative number indexes from the end (-1 is the last argument). Otherwise, index must be the string "#", and select returns the total number of extra arguments it received.

setmetatable (table, metatable) Sets the metatable for the given table. (To change the metatable of other types from Lua code, you must use the debug library (§6.10).) If metatable is nil, removes the metatable of the given table. If the original metatable has a __metatable field, raises an error. This function returns table.

string.byte (s [, i [, j]])s[i]s[i+1]s[j]ijistring.sub Numeric codes are not necessarily portable across platforms.

string.char (···) Numeric codes are not necessarily portable across platforms.

string.dump (function [, strip]) Returns a string containing a binary representation (a binary chunk) of the given function, so that a later load on this string returns a copy of the function (but with new upvalues). If strip is a true value, the binary representation may not include all debug information about the function, to save space. Functions with upvalues have only their number of upvalues saved. When (re)loaded, those upvalues receive fresh instances containing nil. (You can use th

string.find (s, pattern [, init [, plain]]) Looks for the first match of pattern (see §6.4.1) in the string s. If it finds a match, then find returns the indices of s where this occurrence starts and ends; otherwise, it returns nil. A third, optional numeric argument init specifies where to start the search; its default value is 1 and can be negative. A value of true as a fourth, optional argument plain turns off the pattern matching facilities, so the function does a plain "find substring" o

string.format (formatstring, ···) Returns a formatted version of its variable number of arguments following the description given in its first argument (which must be a string). The format string follows the same rules as the ISO C function sprintf. The only differences are that the options/modifiers *, h, L, l, n, and p are not supported and that there is an extra option, q. The q option formats a string between double quotes, using escape sequences when necessary to ensure that it can saf

string.gmatch (s, pattern)pattern§6.4.1spattern As an example, the following loop will iterate over all the words from string s, printing one per line: s = "hello world from Lua" for w in string.gmatch(s, "%a+") do print(w) end The next example collects all pairs key=value from the given string into a table: t = {} s = "from=world, to=Lua" for k, v in string.gmatch(s, "(%w+)=(%w+)") do t[k] = v end For this function, a caret '^' at the start of a pattern does not work as an anchor, as