Operators in Lua: Arithmetic, Comparison, and Logical Operators

What Are Operators?

An operator is a symbol or keyword that tells Lua to perform an operation on one or more values.

Every operator works with:

• • Operands → the values being operated on
• • Operation → the action performed
• • Result → the output produced

Example:

result = 10 + 5

Here:

• • 10 and 5 are operands
• • + is the operator
• • result stores the output

Categories of Operators in Lua

Lua operators are grouped into several categories:

This lesson focuses on the three most important categories:

• • Arithmetic
• • Comparison
• • Logical

Arithmetic Operators in Lua

Arithmetic operators are used to perform mathematical calculations.

Lua supports the following arithmetic operators:

Each operator is explained in depth below.

Addition Operator (+)

The addition operator adds two numbers.

sum = 10 + 20
print(sum)

Output:

30

Addition is commonly used for:

• • Scores
• • Counters
• • Totals
• • Accumulated values

Subtraction Operator (-)

The subtraction operator subtracts one number from another.

difference = 50 - 15
print(difference)

Output:

35

Subtraction is often used for:

• • Health reduction in games
• • Countdown timers
• • Resource consumption

Multiplication Operator (*)

The multiplication operator multiplies two numbers.

product = 6 * 7
print(product)

Output:

42

Multiplication is useful for:

• • Scaling values
• • Calculating areas
• • Damage multipliers

Division Operator (/)

The division operator divides one number by another.

result = 20 / 4
print(result)

Output:

5.0

Floor Division Operator (//)

Floor division divides numbers and rounds the result down to the nearest integer.

value = 7 // 2
print(value)

Output:

3

Floor division is useful when working with:

• • Grid systems
• • Index calculations
• • Discrete units

Modulus Operator (%)

The modulus operator returns the remainder of a division.

remainder = 10 % 3
print(remainder)

Output:

1

Modulus is commonly used for:

• • Checking even or odd numbers
• • Cycling through values
• • Timers and loops

Exponentiation Operator (^)

The exponentiation operator raises a number to a power.

power = 2 ^ 3
print(power)

Output:

8

Exponentiation is used for:

• • Growth formulas
• • Physics calculations
• • Advanced math

Operator Precedence (Arithmetic)

Operator precedence determines the order of execution in expressions.

Lua follows standard mathematical rules:

1. Exponentiation (^)
2. Multiplication, Division, Floor Division, Modulus (*, /, //, %)
3. Addition and Subtraction (+, -)

Example:

result = 10 + 2 * 5
print(result)

Output:

20

Multiplication happens before addition.

Using Parentheses

Parentheses override precedence.

result = (10 + 2) * 5
print(result)

Output:

60

Arithmetic with Variables

Operators work with variables the same way they work with numbers.

local a = 10
local b = 3
local result = a * b + 2
print(result)

Common Arithmetic Mistakes

• Dividing by zero
• Forgetting operator precedence
• Using % incorrectly
• Assuming integer division

Understanding arithmetic operators prevents logic bugs.

Practice Task (Arithmetic)

1. Create two number variables
2. Perform all arithmetic operations on them
3. Print each result
4. Use parentheses to change precedence

Part 1 Summary

In this part, you learned:

• What operators are
• How arithmetic operators work
• Operator precedence
• How to control execution order

These concepts are essential for all future Lua logic.