(Q) More information: cppreference.com¶

Goal: I can find more information about STL containers and their methods.

Instructions: From cppreference.com, you can find lot of more information about C++ and STL containers. On this course, we are studying only the containers vector, set, and map. The sections concerning them can be found from the links:

You can also find the sites above by googling. If you, for example, need more information on a vector, you can use the keywords:

C++ vector

Answers to the question below can be found from the aforementioned links (and from the Plussa material). Only the aforementioned three containers will be considered in the questions.

Question 1

* Method insert:

Which of the containers under consideration have method insert?

Only set and map have insert method.

Only vector and set have insert method.

Only vector and map have insert method.

All the containers under consideration (vector, set, map) have insert method.

Question 2

* Method erase:

Which of the containers under consideration have method erase?

Only set and map have erase method.

Only vector and set have erase method.

Only vector and map have erase method.

All the containers under consideration (vector, set, map) have erase method.

Question 3

* Method find:

Which of the containers under consideration have method find?

Only set and map have find method.

Only vector and set have find method.

Only vector and map have find method.

All the containers under consideration (vector, set, map) have find method.

Question 4

* Adding a new element in a vector:

Vector has the methods insert and push_back for adding new elements. What are the differences and similarities between these methods?

With push_back, you can add a new element only at the end of the vector.

With insert, you can add a new element at the end of the vector.

As their parameter, both the methods have an element to be added and an iterator.

With insert, the new element will be added after the iterator given as a parameter.

From these methods, push_back is more efficient than insert.

Question 5

* Indexing a vector:

In indexing a vector, you can use either at method or [] operator (operator[]). What is the difference between these indexing ways?

at is more complex.

[] is more complex.

at checks if any over-indexing happened.

[] checks if any over-indexing happened.

Question 6

* Indexing vs adding an element:

Also a map has the aforementioned ways to index (at and []). Is it possible to use these also for adding an element?

at of vector can be used for adding an element.

[] of vector can be used for adding an element.

at of map can be used for adding an element.

[] of map can be used for adding an element.

Question 7

* Iterator invalidation:

Sometimes an iterator can become invalid. With which methods and which containers this can happen?

insert can invalidate an iterator of any container under consideration (vector, set, map).

erase can invalidate an iterator of any container under consideration (vector, set, map).

Neither method (insert or erase) invalidates iterators.

insert can invalidate an iterator of vector, but not that of set or map.

Question 8

* Types of elements and keys:

Which types are (naturally, with no special actions) possible for the elements and keys of containers?

map can have a string as its key.

map can have a struct as its key.

map can have a struct as its element.

set can have a struct as its element.

vector can have a struct as its element.

Question 9

* Indexing a container:

Both vector and map have method at for indexing. How does this method differ in these containers?

The type of the parameter passed to at of map can be any of the following ones: int, float, string.

The type of the parameter passed to at of vector can be unsigned int.

The compiler informs about an error, if the value of the parameter passed to at of vector is negative.

It is not necessarily an error, if a negative value is passed to at of map.