To get direct access to variables and methods defined in the standard libraries that come in C++... cout and cin are a good example of this...if you don't declare "using namespace std" at the begining of your code then you will have to use std::cout and std::cin each time you ...
I wanted to know the use namespace from day 1. I thought why do we write "using namespace std;". I got the answer that it is so because we in c++ 11th standard, cout is
What is the output of the following code? #include using namespace std; class A {}; class A2 {char d,e;}; struct B{}; struct C{ char x,y;}; struct D{int x,y;}; main() { cout< cout< A. *p1=new A(); B. p2; 相关知识点: ...
what is the output the following code?#include using namespace std;class A1 { public: int a; static int b;A1(); ~A1();};class A2 { public: int a; char c; A2(); ~A2();};class A3 { public: float a; char c; A3(); ~A3();};class A4 { public: float a; int b; char...
Let us use an example program to demonstrate this: #include <iostream> using namespace std; intmain() { intnum1; floatnum2; string str; cout<<"Please enter an integer value to find its memory address: "; cin>>num1; cout<<"Entered number is: "<<num1<<endl; ...
using namespace std; voidprintInt(int*num){ cout<<"The integer is: "<<*num<<endl; } intmain(){ intx=10; int*ptr=&x; printInt(ptr); return0; } 2:In C, you can convert the void pointer to another pointer type throughimplicit conversion.But in C++ you have to use theexplicit...
Learn: What is thedifference between cout and std::cout, how to use cout's different forms? How can we use cout with and without using 'std::'? coutandstd::coutboth are same, but the only difference is that if we usecout, namespacestdmust be used in the program or if you are ...
usingnamespacestd;tell the compiler "take everything that's in the std namespace and dump it in the global namespace". This allows you to usecoutwithout the std:: prefix, but it increases the probability for name conflicts, since a bunch of extra names that you didn't expect also got...
In country Light Tower, a presidential election is going on. There are two candidates, Mr. X1and Mr. X2, and both of them are not like good persons. One is called a liar and the other is called a maniac. They tear(Chinese English word, means defame) each other on TV face to face...
When you use a C++ vector, it will insert new elements at the end in differential time. This is because, in some cases, the vector will have to expand to accommodate the new element. Similarly, if you were to extract the last element of a vector, it would take constant time the vecto...