C++ Vectors Review

Which of the following statements is true about vectors?

• Vectors allow you to store multiple values in a single variable

• Vectors can only hold one type of value

• Vectors are dynamic and can grow in size

• All of the other options are true

Which of the following is NOT a correct way to create a vector?

• vector<string> greeting {"Hello", "Hola"};

• vector<int> nums {3, 6, 7.8, 9};

• vector<bool> option {true};

• All of the options are correct

What will be printed from the following code snippet?

vector<string> count {"One", "Two", "Three"};

cout << count.at(1) << endl;

cout << count[2] << endl;

• 1

  2

• One

  Two

• Two

  Three

• Three

Which statement best describes the actions of the push_back command?

• push_back adds a new element to the front of the vector, pushing all of the elements back 1 index and increasing the overall size by 1.

• push_back adds a new element to the end of the vector, increasing the size by 1.

• push_back replaces the first element in the vector.

• push_back replaces the last element in the vector.

What does the following code segment return?

vector<string> lang {"C++", "Java", "Python", "JavaScript"};

cout << lang.at(lang.size() - 2) << endl;

• C++

• Java

• Python

• JavaScript

What will print from the following code snippet?

vector<double> constants {3.14, 2.718, 0.577};

constants.pop_back();

constants.push_back(constants.size());

cout << constants[2] << endl;

• 2

• 3

• 2.718

• 0.577

Which of the following code segments will print all members of an int vector v?

• 1 only

• 2 only

• Neither 1 or 2

• Both 1 and 2

Which of the following statements is true about traversing a vector?

• for-each loops and for loops are completely interchangeable

• A benefit of the for-each loop is that it is easier to read and code

• A benefit of the for-each loop is that it has a tracker variable to reference the index

• Both for-each and for loops access the values of the vector via the vector’s index value

What would be the output from the following code snippet?

• 3 5 2 6 9 3

• 9 6 9

• 6 3 2 6

• The code will print an error.

What is the main difference between an array and a vector in C++?

• Arrays can store multiple data types, vectors cannot

• Vectors can grow or shrink in size, but arrays cannot

• Arrays can be resized dynamically, vectors cannot

• None of the options is correct.