Practice

Lua exercises

Make a change, predict what it will do, and compare the result.

1
Lua Basics
Store a local value and print it.
Adapt the lesson example. Change one value or element, predict the result, and explain why it changes.
Review lesson →Open compiler
Show starting example
Lua
```
local name = "Ada"
print("Hello, " .. name)
```
2
Lua Functions
Write a local function that loops over a table and returns a result.
Predict average({1, 2}) without math.floor on Lua 5.4.
Reveal answer and reasoning
It returns 1.5, because 3 / 2 uses floating-point division.
Review lesson →Open compiler
Show starting example
Lua
```
local function average(values)
  local total = 0
  for _, v in ipairs(values) do
    total = total + v
  end
  return total / #values
end

print(math.floor(average({82, 91, 76, 95})))
```
3
Lua Loops
Count with a numeric for and repeat with while.
What is printed for n if it starts at 6?
Reveal answer and reasoning
6 → 4 → 2; at 2 the condition is false, so it prints 2.
Review lesson →Open compiler
Show starting example
Lua
```
for i = 1, 3 do
  print(i)
end

local n = 5
while n > 2 do
  n = n - 2
end
print(n)
```
4
Lua Tables
Use one table type as both an array and a record.
What does scores[#scores] return after the insert?
Reveal answer and reasoning
The last element, 95.
Review lesson →Open compiler
Show starting example
Lua
```
local scores = {82, 91, 76}
table.insert(scores, 95)
print(#scores .. " " .. scores[1])
local person = {name = "Ada", age = 36}
person.age = person.age + 1
print(person.name .. " " .. person.age)
```