Lua Quick Start Guide

Logical operators

Logical operators test the relationship of two statements. Logical operators work a little differently in Lua than in other languages. In Lua, anything not false is considered to be true. Only two values represent false for a logical operator, the constant value of false and nil; anything else is true.

Logical operators in Lua do not evaluate to a Boolean result; rather they evaluate to one of the provided operands.

The and operator returns its first operand if that operand is false and the second operand if the first operand was true. Here is an example:

x = true and false -- value is falsey = false and false -- value is falsez = true and true -- value is truew = 7 and 1 -- value is 1

The or operator (or) returns its second ...