Accessing - Bracket Notation

Part of the Fundamentals section of Coddy's Lua journey — lesson 66 of 90.

To access a value in a dictionary-style table, you use the key inside square brackets.

The syntax for accessing values with bracket notation is straightforward:

local player = {
    ["name"] = "Alex",
    ["score"] = 1500,
    ["level"] = 8
}

print(player["name"])   -- outputs: Alex
print(player["score"])  -- outputs: 1500

You simply write the table name, followed by square brackets containing the key as a string. This tells Lua to look up that specific key and return its corresponding value.

local monster = {
    ["type"] = "Dragon",
    ["hp"] = 200,
    ["damage"] = 50
}

local currentHealth = monster["hp"]
print(currentHealth)  -- outputs: 200

Challenge

Easy

Create a dungeon exploration system that demonstrates accessing monster information using bracket notation. First, create a table named monster with the following key-value pairs: ["type"] should be assigned the string "Orc", ["health"] should be assigned the number 75, ["attack"] should be assigned the number 15, and ["defense"] should be assigned the number 8. After creating the table, use bracket notation to access and print the monster's health value.

Cheat sheet

To access values in a dictionary-style table, use the key inside square brackets:

local player = {
    ["name"] = "Alex",
    ["score"] = 1500,
    ["level"] = 8
}

print(player["name"])   -- outputs: Alex
print(player["score"])  -- outputs: 1500

You can also store accessed values in variables:

local currentHealth = monster["hp"]
print(currentHealth)  -- outputs the hp value

Try it yourself

-- TODO: Create the monster table with the required key-value pairs

-- TODO: Use bracket notation to access and print the monster's health value

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Fundamentals

1Introduction

The Language Hello World!Comments

4Operators 2 Relational & Logic

Equality Operators Relational Operators The 'and' Operator The 'or' Operator The 'not' Operator Short-Circuit Evaluation Truthy and Falsy Values Recap - Simple Logic

7Basic Conditional Logic

The if-then Statement The if-then-else Statement The elseif Statement Recap - Treasure Chest

10Tables Part 1: List-Style

What is a Table?Creating a Table Accessing Elements by Index Modifying Elements by Index The Length Operator '#'table.insert()table.remove()Recap - Manage Party Members

13Project: Simple Potion Shop

Project Setup Adding a Potion

Displaying the Inventory

Calculating Total Stock Value

Finding a Specific Potion

Selling a Potion

2Variables and Data Types

What is a Variable?Numbers Strings Booleans The Value 'nil'The type() Function Naming Conventions Recap - Character Profile

5Basic Output

Printing Literals Printing Variables Printing Multiple Values Combining Strings & Variables The tostring() Function Input Cast Recap - Status Report Recap - Till 120

8String Manipulation Basics

string.len()string.upper & string.lower string.sub()string.rep()string.find()Recap - Format Username

11Tables 2: Dictionary-Style

Key-Value Pairs Creating Dictionary-Style TablAccessing - Bracket NotationAccessing with Dot Notation Adding and Modifying Pairs Removing Pairs with nil Recap - Item Properties

14Variable Scope

Global Variables Local Variables Why Use Local Variables?Scope and Blocks Recap - Scope Puzzle

3Operators 1 Arithmetic & Conc

Arithmetic Operators Modulo Operator Exponentiation Operator String Concatenation Operator Precedence Recap - Simple Calculations

6Project: Character Stats Disp

Welcome Message Declare Character Stats

Display Basic Stats

Add a Boolean Flag

Final Summary

9Functions Basics

Declaring a Function Calling a Function Functions with Parameters Functions with Multiple Params The 'return' Statement Recap - Area Calculator

12Loops Basics

The while Loop The repeat-until Loop The Numeric for Loop for Loop with a Step The 'break' Statement Recap - Countdown

15Final Challenges

Recap - Player Turn Recap - Simple Database Recap - Sum of Even Numbers