Comp Sci Ch 9 Ch 10 Flashcards
what types of ordered list types does c++ suppport
arrays and vectors
how do you declare vectors
vector<type> name (elements)</type>
how do you access an index of a vector
name.at(i);
why are vectors safer than arrays
because it uses () that check the .at while the [] in arrays are not
AND
arrays do not have the size feature
what is a vector
an ordered list of items of a given data type
what is an element in a vector
each item
what do you need to include to use vectors
include < vector>
If a vector has N elements
what is the last element index
N - 1
if a vector has last index N, how many elements does it have
N + 1
The index of a vector to access must be
an unsigned int type and not a floating type number
what does size return for a vector
the number of elements
when a vector is initialized with a number of elements
vector<type> name (numOfElements);</type>
what are the elements initialized to
0
how to initialize all the elements of a vector to one value
vector <type> name ( numOfElements, valueToSetTo);</type>
how to initialize each element in a vector to different values
vector <type> name = {num, num, ...};</type>
for a large vector how should you initialize it
a for loop
normal loop header for iterating through a vector
for ( unsigned int i = 0; i < v.size(); ++i) {
//loop body;
}
you already have the vector size
how should you input stuff into the vector
for ( unsigned int i = 0; i < v.size; ++i) {
cin»_space; v.at(i);
}
If you have multiple vectors….
both vectors should have same amount of elements
–0 corresponds to 0 and 1 to 1 and so on
how do you append items to a vector
.push_back
how to use .back()
to return a vectors last element and vector is unchanged
what does .pop_back() do
removes last element and changes vector
does the size of a vector have to specified in the declaration
no
instead of (numElements) just ;
what is .resize() for
to change the size of the vector
how does = compare vectors
copies all of one vector to another vector
how does == compare vectors
compared elements by elements
true if same size and each element pair is equal
how should you reverse a vector
–iterate size/2
–need a temp value to hold the value at i
–set that i equal to the last value size - 1- i
–make the last element the —temp value
vectors with….should be passed by
10 by reference
then check if should be constant
what is an object
a grouping of data (variables) and operations that can be preformed on that data (functions) in a class
what is abstraction
having a user interact with an item at a high level with lower level internal details hidden from user
what is abstraction also thought of
info hiding or encapsulation
what does abstraction mean in a class
hiding entire groups of functions and variables exposing only certain functions to a user
what is abstract data type
a data type whose creations and update are constrained to specific well-defined operations - use a class to implement
what is a class
defines a new type that can group data and functions to form an object
what are public member functions
indicate all operations a class user can preform on the object
how to declare a class
class name {
public:
functions
return type name ( type parameter)
private:
typically variables that public functions use;
};
how to call a class in main
class name object name;
object name. public functions (parameters);
what is the dot operator / member access operator do
used to invoke a function on an object
the string data type is an example of a …
class
what are private data members
variables that member functions can access but class user cannot
main can access…but cannot access
public member functions
private data members
each function declaration under public in a class needs to be….
defined outside of the class
the function declaration in the class has and the function definition has
declaration -
return type name ( type parameter);
definition-
return type class :: name (type parameter) {
statements
}
when defining a member function with parameters you do not need to…
declare the variables you will use because they have been declared in the class, just call them
a class public functions are commonly classified as either
mutator or accessors
what is a mutator
function may modify (mutate) a class data member
–sets the value
what is an accessor
function accesses data members but does not modify data members
–gets the value
what are private helper functions
private functions to help public functions carry out tasks
—cane be called by private and public , not by main
can you initialize data members in class definition
yes, any variable declared in that class type will have those initial values
what is a constructor, where called and how defined, and what happens if there is no user defined one
called automatically when a variable of that class type is declared and which can initialize data members
–called inside public as class name() (no return type)
–defined out of the class as
class name :: class name (){
initializing data members
}
if no user defined one, complier implicitly defines a default but having no statements
