Section quiz

Your first program

Nine questions on the compiler, the five lines of hello, the errors you have already met on purpose, and reading input.

Questions are shuffled within each part, and so are the answers. You can retake it as often as you like.

0 of 9 answered

Part 1: How a C++ program gets built

Question 1

The compiler reports eighteen errors from one file. What is the best next move?

A.Start with the shortest message, since it is likely to be the simplest problem.B.Fix all eighteen, then compile once, to save time.C.Fix the first error only, then compile again.D.Start with the last error, since the earlier ones are usually caused by it.

Question 2

A file compiles with no errors, but the build fails with undefined reference to 'main'. What has gone wrong?

A.The compiler translated the file successfully, and the linker then found no main to start the program from.B.#include <iostream> is missing from the top of the file.C.There is a syntax error somewhere inside main that the compiler missed.D.main was used before it was declared, so it needs a declaration higher up the file.

Question 3

What does #include <iostream> actually do?

A.It tells the linker which library file to join your code to at the end.B.It pastes the contents of the iostream header into your file before the compiler reads it.C.It makes the names in std available, so cout can be written without a prefix.D.It loads a library into memory while your program is running.

Question 4

A 60 line program has a mistyped name on line 40. You press run. What happens?

A.The program runs normally and prints a warning at the end.B.The program runs from start to finish and quietly skips line 40.C.Nothing runs at all. The compiler stops and no executable is produced.D.Lines 1 to 39 run, then the program stops with an error at line 40.

Question 5

The compiler reports main.cpp:6:5: error: expected ';' before 'return'. Line 6 is return 0;, which looks perfectly correct. What is wrong?

A.main must return a value other than 0 for the program to build.B.The semicolon on line 6 is indented into the wrong column.C.Line 5 is missing its semicolon, and line 6 is the first thing that could not follow it.D.return 0; should be written as return; inside main.

Part 2: Output and input

Question 6

A program contains, in this order, std::cout << "red"; then std::cout << "green"; then std::cout << "blue";. What appears on the screen?

A.Only blue, because each one replaces what was there beforeB.The three words, each on a line of its ownC.red green blue, with a space between each pairD.redgreenblue, all on one line

Question 7

The input is one line reading Ada Lovelace. The program does std::string s; std::cin >> s;. What is in s afterwards?

A.Ada LovelaceB.AdaLovelace, with the space taken outC.AdaD.Nothing, because a std::string read this way cannot contain a space

Question 8

What does std::cout << "3 + 4"; put on the screen?

A.3 + 4B.Nothing, because a sum cannot be placed inside quotation marksC.7D."3 + 4"

Question 9

A program reads a seat count with std::cin >> seats; and then reads a customer name with std::getline(std::cin, name);. The name always comes back empty, and the program never pauses for it. Why?

A.std::getline may only be used before any >> in the same program.B.The number and the name have to be typed on the same line for this to work.C.name was never given a size, so there was nowhere for the text to go.D.>> left the newline at the end of the number in the input, and getline read up to it immediately.

9 questions left to answer.