string.upper

local result = string.upper(input)

--Convert to uppercase
local result = string.upper("hello")
engine.print(result) --HELLO

--Mixed case
local result = string.upper("Hello World")
engine.print(result) --HELLO WORLD

--Already uppercase (no change)
local result = string.upper("ALREADY UPPERCASE")
engine.print(result) --ALREADY UPPERCASE

--Numbers and special characters unchanged
local result = string.upper("abc123!@#")
engine.print(result) --ABC123!@#

--Case-insensitive comparison
local str1 = "Hello"
local str2 = "hello"
if string.upper(str1) == string.upper(str2) then
    engine.print("Strings are equal (case-insensitive)")
end

--Normalize user input
local input = "yes"
if string.upper(input) == "YES" then
    engine.print("User confirmed")
end

--Create constant names
local varName = "max_value"
local constant = string.upper(varName)
engine.print(constant) --MAX_VALUE

--Emphasize text
local text = "warning"
local emphasized = string.upper(text)
engine.print(emphasized) --WARNING

--Convert enum values
local status = "active"
local enum = string.upper(status)
engine.print(enum) --ACTIVE

--String with only numbers (no change)
local result = string.upper("123456")
engine.print(result) --123456

--Empty string
local result = string.upper("")
engine.print(result) --

--Title to header
local title = "my document title"
local header = string.upper(title)
engine.print(header) --MY DOCUMENT TITLE

--SQL-like syntax
local column = "user_id"
engine.print(string.upper(column)) --USER_ID

--Compare ignore case
local function equalsIgnoreCase(a, b)
    return string.upper(a) == string.upper(b)
end
engine.print(equalsIgnoreCase("Test", "test")) --true

--Format command
local cmd = "help"
engine.print("Command: "..string.upper(cmd)) --Command: HELP

--Acronym from words
local text = "hypertext markup language"
local acronym = ""
for word in string.gmatch(text, "%S+") do
    acronym = acronym..string.upper(string.sub(word, 1, 1))
end
engine.print(acronym) --HML

--Shouty snake case
local name = "my_variable_name"
local shouty = string.upper(name)
engine.print(shouty) --MY_VARIABLE_NAME