3.1 Functions: Definition and Calls

Step 1 — Recall what a function call looks like: A call is a name followed by parentheses, which means "run it now."

Step 2 — Check each line: Line 1 (let inputNum = 14;) is an assignment. Line 2 (let offsetNum = inputNum - 10;) is also an assignment with only arithmetic. Line 3, console.log(offsetNum);, has the name console.log followed by parentheses.

Answer: c. line 3

Step 1 — Scan for every console.log( occurrence: Line 1: console.log("Please log in") — yes. Lines 2 and 3 use prompt(), not console.log(). Line 4: console.log("Login successful") — yes. Line 5: console.log("Welcome,", username) — yes.

Step 2 — Count: That gives three calls to console.log() (the two prompt() calls are function calls too, but not of console.log()).

Answer: b. 3

Step 1 — Count calls line by line: Line 1: Number(...) and inside it prompt(...) — two calls. Line 2: Number(...) and prompt(...) again — two more calls. Line 3: console.log(...) — one call.

Step 2 — Total: \(2 + 2 + 1 = 5\) calls.

Answer: b. 5

Step 1 — Compare against the definition format: A header must be function name() { — the keyword, then the name, then parentheses, then {.

Step 2 — Check each option: Option a is wrong because indentation is a convention, not required in the header. Option c is wrong because the keyword is function, not func. The missing piece in function waterPlant { is the empty pair of parentheses after the name.

Answer: b. Parentheses should go after waterPlant.

Step 1 — Trace execution order: Statements run top to bottom. First, the function definition is stored but its body does not run yet. Then console.log("User info:") executes and prints User info:.

Step 2 — Run the call: Next, printPhoneNum(); jumps into the body and prints Phone: (864) 555-0199. So option c is wrong (the function is called), and option a has the order reversed.

Answer: b. User info: then Phone: (864) 555-0199

Step 1 — Apply the "parentheses mean run it" rule: Writing just printPcSpecs names the function without running it. Writing function printPcSpecs() starts a definition, not a call.

Step 2 — Identify the call: Only printPcSpecs() — name plus parentheses as a statement — actually invokes the function.

Answer: b. printPcSpecs()

Step 1 — Check naming rules: A JavaScript identifier cannot contain spaces, so calculate user tax is invalid syntax.

Step 2 — Check readability and convention: cT is legal but tells a reader nothing. calcTax is descriptive, uses camelCase, has no spaces or underscores — exactly what conventions call for.

Answer: a. calcTax

Step 1 — Count in the "before" version: Each of the three distances uses one line declaring four coordinate variables and one line doing the math with those coordinates — so 6 lines mention coordinate values (\(3 \times 2\)).

Step 2 — Count in the "after" version: Each distance is computed by passing coordinates directly into one calcDistance(...) call — 3 lines total.

Answer: b. 6 and 3

Step 1 — Recall reusability: A function definition places no limit on how many times it can be invoked. Every call simply runs the same body again.

Step 2 — Evaluate the options: "Once" and "three times" would be arbitrary restrictions that don't exist in the language.

Answer: c. as many times as you like

Step 1 — Explain why nothing prints: Defining a function only stores its code — the body never runs until the function is called. This program defines showMenu() but never calls it, so no output appears.

Step 2 — Fix it: Add a call statement after the definition:

function showMenu() {
  console.log("1. Start  2. Options  3. Quit");
}

showMenu();

Now the call showMenu(); makes the body execute and the menu prints.

Answer: The program prints nothing because showMenu() is defined but never called; adding the call showMenu(); fixes it.

Step 1 — Define the function: Create a parameterless function whose single job is printing the options line.

function concessions() {
  console.log("Food/Drink Options: Popcorn: $8-10 Candy: $3-5 Soft drink: $5-7");
}

Step 2 — Call it: Without a call the body never runs, so add concessions(); after the definition.

concessions();

Output:

Food/Drink Options: Popcorn: $8-10 Candy: $3-5 Soft drink: $5-7

Answer: The complete program is the concessions() definition above followed by the call concessions();, which produces exactly the required output.

Step 1 — Define the reusable part: Put the ask-and-respond logic in one function so it can be called once per user.

function terms() {
  console.log("Do you accept the terms and conditions?");
  const answer = prompt("Enter Y or N:");
  if (answer === "Y") {
    console.log("Thank you for accepting.");
  } else {
    console.log("Have a good day.");
  }
}

Step 2 — Read the number of users and loop: Read a count with prompt() converted via Number(), then call terms() once per user in a loop.

const numUsers = Number(prompt("How many users?"));
for (let i = 0; i < numUsers; i++) {
  terms();
}

Step 3 — Verify against the sample runs: With 1 user answering Y, the loop runs once and prints the question then "Thank you for accepting." With 2 users answering N then Y, the question/response pair appears twice, first with "Have a good day." then with "Thank you for accepting." Both match the expected output.

Answer: The program above writes the interaction once in terms() and calls it once per user in a loop, producing exactly the sample outputs shown.