Arithmetic operators

Arithmetic operators do math; these operators work on numbers to perform addition, subtraction, multiplication, and division. Operators to find the remainder of a division, negate a number, or raise a number to a power are also available in Lua. The negation operator uses a minus sign and is a unary operator; otherwise, all other arithmetic operators are binary operators (that is, they work on two operands).

The addition operator (+) adds two operands together:

x = 7 + 10
y = x + 3
z = x + y

The subtraction operator (-) will subtract the second operand from the first:

x = 8 - 3
y = 10 - x
z = x - y

The multiplication operator (*) will multiply the given operands:

x = 2 * 2
y = x * 3
z = x * y

The division operator (/) will divide the numerator (first operand) by the denominator (second operand):

x = 20 / 10
y = 5 / x
z = x / y

The modulus operator (%) returns the remainder of an integer division. This means both the numerator (first operand) and denominator (second operand) are cast to be integers, divided, and the result is returned. Numbers are cast to integers, not rounded. This means that any decimal numbers are discarded, so 5.1, 5.5, and 5.9 would all simply become 5. Here is an example:

x = 5 % 2 -- result is 1
y = 5.7 % 2 -- 5.7 is treated as 5, result is 1.
z = 5.3 % 2.9 -- result is 1

The negation operator (-) negates a number. This is the only unary arithmetic operator. Here is an example:

x = -5 -- x = -5
y = -x -- y = 5
y = -y -- y = -5

The exponent operator (^) will take the base (first operand) and raise it to the power of the exponent (second operand):

x = 10 ^ 2
y = x ^ 2
z = 3 ^ 3