string.match

local ... = string.match(input, pattern, start_at = 1)

--Match and return entire pattern
local result = string.match("hello 123", "%d+")
engine.print(result) --123

--Match with single capture
local num = string.match("Price: $25", "%$(%d+)")
engine.print(num) --25

--Multiple captures
local word1, word2 = string.match("hello world", "(%a+) (%a+)")
engine.print(word1, word2) --hello  world

--Extract email parts
local user, domain = string.match("john@example.com", "(.+)@(.+)")
engine.print(user) --john
engine.print(domain) --example.com

--Match with starting position
local result = string.match("hello hello", "hello", 7)
engine.print(result) --hello

--Extract number from string
local num = string.match("Temperature: 25°C", "%d+")
engine.print(num) --25

--Extract quoted text
local text = 'name="John Doe"'
local value = string.match(text, '"(.-)"')
engine.print(value) --John Doe

--Match URL components
local url = "https://example.com/path"
local protocol, domain, path = string.match(url, "(.-)://([^/]+)(.+)")
engine.print(protocol) --https
engine.print(domain) --example.com
engine.print(path) --/path

--No match returns nil
local result = string.match("hello", "%d+")
engine.print(result) --nil

--Extract version number
local version = string.match("v1.2.3", "v(%d+%.%d+%.%d+)")
engine.print(version) --1.2.3

--Match first word
local word = string.match("  hello world  ", "%a+")
engine.print(word) --hello

--Extract hexadecimal color
local color = string.match("color: #FF5733", "#(%x+)")
engine.print(color) --FF5733

--Validate and extract
local text = "user123"
local name = string.match(text, "^(%a+%d+)$")
if name then
    engine.print("Valid username:", name)
end

--Extract key-value pair
local key, value = string.match("setting=enabled", "(.-)=(.*)")
engine.print(key, value) --setting  enabled

--Capture position (empty capture)
local text = "hello world"
local pos = string.match(text, "world()")
engine.print(pos) --12