print(string.upper("hello"))
print(string.lower("WORLD"))
print(string.len("luna"))
print(#"abcdef")
print(string.sub("abcdef", 2, 4))
print(string.rep("ab", 3))
print(string.reverse("hello"))
print(string.byte("A"))
print(string.char(65, 66, 67))
print(string.format("%d %s %f", 42, "test", 3.14))
print(string.format("%5d %-10s|", 7, "left"))
print(string.find("hello world", "wor"))
print(string.match("date: 2026-06-28", "(%d+)-(%d+)-(%d+)"))
print(string.gsub("hello world", "o", "0"))