c primer plus

struct candybar { string brand; float weight; int Carlo; }; Int main () { candybar Snack[3] = {"Mocha Munch", 2.3,350},{" Mocha Middle ", 2.0,300},{" Mocha Little ", 3.2,600}}; for (int i=0;i cout return 0; } 7. Answer#include #include using namespace Std;struct PIZAINFO{String Coname;int diameter;float weight;};int main (){Pizainfo P1;cout cout Getline (Cin,p1.coname);cout cin>>p1.diameter;cout CIN >>p1.weight;cout}8. Answer#include #include using namespa

the type of PG can be safely converted to superb*, if possible, return the address of the object, otherwise, return a null pointer.Dynamic_casttypeID makes it possible to determine whether two objects are of the same type and accepts two parameters: the class name and the expression that the result is an object. The return value is a reference to the Type_info object.typeID (Magnificent) ==typeid (*PG);A null pointer to PG throws an exception Bad_typeid. Type_info contains the name () function,

Procedural programming and object-oriented programmingObject-oriented Programming (OOP) Features: Abstract Encapsulation and data hiding Polymorphic Inherited Reusability of code Abstractions and classesA class is a C + + tool that translates abstractions into user-defined types, which synthesize a concise package of data representation and manipulation of data.Constructors and destructors for classesConstructor: Same as class nameDestructor: ~ Class nameObject Initialization

1. What is the role of #include This compilation instruction causes the preprocessor to add the contents of the iostream file to the program, which is a typical preprocessing operation that replaces or adds text before the source code is compiled.Io in iostream refers to input and output, and the input/output scheme in C + + involves multiple definitions in a iostream file, in order to display messages using cout, the first program needs these definitions, #include The compile instruction causes

Fifth cycle and relationship expressions1.2. Category aliases:(1) #define Float_pointer FLOAT *Float_pointer PA, PB; Preprocessor substitution converts the declaration into a float * pa, PB;//PA is a pointer, PB is a float(2) typedef char BYTE does not appear above the problem is the best choice3, Cin.get (name, arsize). Get ()//Enter a name with a length of arsize to accept line breaksThe input sent to CIN is buffered. This means that only the user presses the carriage return and the content th

characteristics.16.4.2 iterator TypeThe STL defines five types of iterators: an input iterator, an output iterator, a forward iterator, a bidirectional iterator, and a random iterator.16.4.3 iterator Hierarchy......16.4.4 concepts, improvements and models......16.4.5 container TypeThe previous 11 container types were: Deque,list,queue,priority_queue,stack,vector,map,multimap,set,multiset,bitsetC + + has new forward_list,unordered_map,unordered_multimap,unordered_set,unordered_multiset and does

{' L ', ' I ', ' s ', ' P '};16.1.2 String Class inputFor C-style strings, there are 3 ways to enter:Char info[100];CIN >> Info; Read a WordCin.getline (info, 100); Read a line, discard \ nCin.get (info, 100); Read a line, leave \ n in queueFor string objects, there are two ways of doing this:string stuff;CIN >> Stuff; Read a WordGetline (cin, stuff); Read a line, discard \ nTwo versions of Getline () have an optional parameter that specifies which character to use to determine the bounds of th

the container has an iterator concept that supports the algorithm requirements. For example, the For_each () algorithm uses an input iterator, and all STL container class types meet their minimum requirements: while sort () requires a random-access iterator, not all container classes support this iterator. If the container class does not meet the requirements of a particular algorithm, it may provide a dedicated method. For example, the list class contains a sort () method based on a bidirectio

assigned to a unique_ptr in the VP. In addition, if you pass an object by value instead of by reference to show (), the For_each () syntax will be illegal because this will cause the pi to be initialized with a non-temporary unique_ptr from the VP, which is not allowed. In front of the state, the compiler will find an attempt to use unique_ptr incorrectly.When Unique_ptr is the right value, it can be assigned to shared_ptr, which is the same as assigning one unique_ptr to another that needs to

calling function.A class is a user-defined data type specification that describes in detail how information is represented and what operations can be performed on the data. An object is an entity created from a class specification, just as a simple variable is an entity created from a data type description.C + + provides two predetermined objects (CIN and cout) for processing inputs and outputs, which are instances of the IStream and Ostream classes that are defined in the iostream file. The in

Programs and programming are more interesting when you use the bootstrapper to select statements for different actions. C + + provides an if statement, if Else statement, and a switch statement to manage options. An If statement enables a program to execute a statement or block of statements conditionally, that is, if a specific condition is met, the program executes a specific statement or block of statements. The IF Else statement program chooses to execute one of two statements or blocks of s

precautions are summarized above, which should be kept in mind because the compiler is unaware of these rules and therefore cannot discover errors).* For all Class members assigned by new when pointing to memory, delete should be used in the class's destructor, which frees the allocated memory.* If the destructor frees memory by using delete on pointer class members, each constructor should use new to initialize the pointer, or set it to a null pointer.* You should define a copy constructor tha

function, use the parse operator (::) to identify the class to which the function belongs;* Class methods can access the private components of a class.For example, the function header of the update member function is as follows:void Stock::update (double price)Example: implementation of a classProgram Listing 10.2 Stock00.cpp//Stock00.cpp--Implementing the Stock class//version xx#include #include"stock00.h"voidStock::acquire (ConstSTD::string Co,LongNDoublePR) { Company=Co; if(N 0) {Std::cout"N

automatically.Destructors complete cleanup work, so it's actually useful. Abuse, if the constructor uses new to allocate memory, the destructor uses Delete to free the memory.Destructor Prototypes:~stock ();destructor Definition:Stock::~stock (){cout }When a destructor should be called is determined by the toilet, and usually should not be called in code to call the destructor.If you create a static storage class object, its destructor will be called automatically at the end of the program.If y

member function by using the member operator period: Mr_object.try_me (). In OOP, this function call is referred to as sending the Try_me message to the Mr_object object. When a class data member is referenced in the Try_me () method, the corresponding data member of the Mr_object object is used. Similarly, the function call I_object.try_me () accesses the data member of the I_object object.If you want the member function to operate on more than one object, you can pass the extra object as a pa

Virtual functions of C ++ Primer Plus learning notes There are two types of C ++ polymorphism: static polymorphism and dynamic polymorphism. Function overloading and operator overloading are the specific manifestations of static polymorphism. Dynamic polymorphism is the object for dynamically determining the operation during the program running. It is implemented through virtual functions; 1. Concepts of v

performed) int type The return value of the function when it reaches EOF istream (false after bool conversion) eof After EOF is detected, CIN sets two bits (Eofbit and Failbit) to 1, which can be cin.eof () to see if Eofbit is set, and Cin.fail () can see if Eofbit or Failbit is set The IStream class provides a function that converts a IStream object to a bool value, which is automatically called when Cin appears where the bool value is now

C ++ Primer Plus 6th Reading Notes, primer6th1. Handling line breaks when cin reads errors 1 # include The preceding code is entered in two cases: If the input is double type, cin. get (c) will read the line break and the program is running. If the input is not double type, such as char type, the cin will set the error bit, retain the incorrect input while discarding the carriage return (this is the ca

characters from the streamGcount ()Putback () inserts a character into the beginning of the input stream, reading is the first character15. File input and outputTo add a header file FStreamTo write to a file1. Create a Ofstream object2. Associate the object with a specific file3. Use the Fout in a way that uses coutOfstream Fout;fout.open ("Hjq.txt");Read file1. Create a Ifstream object2. Associate the object with a specific file3. Use fcin in a way that uses CINLast Close Fout.close ()16. Crea

Iostream contains two basic types: IStream and Ostream.The standard library defines 4 IO objects: CIN, cout, Cerr (output warning and error message), clog (general information when the output program runs).Writing data to a streamsuch as:std::coutWhere the "must be an Ostream object, and the operand on the right is the value to be printed. Note: The second operator prints Endl, which is a special value called an operator. The effect of writing it is to end the current line and to brush the conte