Printing versus returning

v6 · Activity 4 of 14 · return-values · functions · 4 min Runs here

Chapter outline

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One step at a time

print displays a value now. return gives a value to the caller to use later. A function that returns no value leaves nil, meaning no value, when its caller stores the result. Compare the two calls and predict all three output lines.

Your task

Observed-output goal: display "5", "nil", "5", in that order. Predict, then run the two examples. Expect 5, nil, and 5. Explain the difference using the self-check; your wording is not graded. Completion checks these outputs and value types only; the example's structure is an experiment, not a required solution.

Which lines appear?5 then 55 then nil then 5nil onlyChoose a prediction, then Run code to compare. This is a self-check.

Expected output

5
nil
5

Lines must stay in order. Spelling, capitalization and spaces inside a message matter.

Syntax in this activity

New syntax: nil

Earlier ideas used here

return-values
functions
local-variables

What this exercise checks

Actual Output · exact lines and order · extra output forbidden.

Successful execution is required. A compile error, runtime error or execution limit never completes this task.

Whitespace, matching single or double quotes, and different variable names are allowed. Output-only tasks accept any valid Luau solution meeting the displayed result and value types. Construct tasks use the stated straight-line form.

Your explanation

Self-check rubric

The first 5 comes from print inside show.
shown has nil because show returns no value.
The final 5 is returned by give and printed by its caller.

Your explanation is a self-check. Exact wording is not automatically graded.

Explain this code

Select a word or symbol in this authored example. Your editor draft stays unchanged.

  amount
     

 saved  amount
saved

Choose a highlighted part to see what it means.

Free experiment

This is a private experiment copy. It does not replace your answer or complete the activity.

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local function amount()
    return 3
end
local saved = amount()
print(saved + 2)

local function amount()
    return 3
end
local saved = amount()
print(saved + 2)

Luau keyword highlighting · Ctrl/⌘ + Enter: Run · Esc: leave editorTab inserts indentation

Experiment Output

Your output will appear here.

Reset starter

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Code

Luau

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local function show()
    print(5)
end
local function give()
    return 5
end
local shown = show()
print(shown)
print(give())

local function show()
    print(5)
end
local function give()
    return 5
end
local shown = show()
print(shown)
print(give())

Luau keyword highlighting · Ctrl/⌘ + Enter: Run · Esc: leave editorTab inserts indentation

Your output will appear here.

Ready