C++ Articles

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static keyword in C++ vs Java

Smita Kapse
Smita Kapse
Updated on 30-Jul-2019 728 Views

In C++ or Java we can get the static keyword. They are mostly same, but there are some basic differences between these two languages. Let us see the differences between static in C++ and static in Java.The static data members are basically same in Java and C++. The static data members are the property of the class, and it is shared to all of the objects.Examplepublic class Test {    static int ob_count = 0;    Test() {       ob_count++;    }    public static void main(String[] args) {       Test object1 = new Test();   ...

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Extending namespace and Unnamed namespace

Nishtha Thakur
Nishtha Thakur
Updated on 30-Jul-2019 370 Views

Here we will see how we can extend some namespace, and how the unnamed or anonymous name space can be used.Sometimes we can define one namespace. Then we can write the namespace again with the same definition. If the first one has some member, and second one has some other members, then the namespace is extended. We can use all of the members from that namespace.Example#include using namespace std; namespace my_namespace {    int my_var = 10; } namespace my_namespace { //extending namespace    int my_new_var = 40; } main() {    cout

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Returning multiple values from a function using Tuple and Pair in C++

Nishtha Thakur
Nishtha Thakur
Updated on 30-Jul-2019 3K+ Views

In C or C++, we cannot return more than one value from a function. To return multiple values, we have to provide output parameter with the function. Here we will see another approach to return multiple value from a function using tuple and pair STL in C++.The Tuple is an object capable to hold a collection of elements, where each element can be of different types.The pair can make a set of two values, which may be of different types. The pair is basically a special type of tuple, where only two values are allowed.Let us see one example, where ...

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Inheritance and friendship in C++

Smita Kapse
Smita Kapse
Updated on 30-Jul-2019 2K+ Views

In C++, the friendship is not inherited. It means that, if one parent class has some friend functions, then the child class will not get them as friend.In this example it will generate an error because the display() function is friend of MyBaseClass but not the friend of MyDerivedClass. The display() can access the private member of MyBaseClass.Example#include using namespace std; class MyBaseClass {    protected:       int x;    public:       MyBaseClass() {          x = 20;       }       friend void display(); }; class MyDerivedClass : public MyBaseClass {    private:       int y;    public:       MyDerivedClass() {          x = 40;       } }; void display() {    MyDerivedClass derived;    cout

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Simulating final class in C++

Anvi Jain
Anvi Jain
Updated on 30-Jul-2019 578 Views

In Java or C#, we can use final classes. The final classes are special type of class. We cannot extend that class to create another class. In C++ there are no such direct way. Here we will see how to simulate the final class in C++.Here we will create one extra class called MakeFinalClass (its default constructor is private). This function is used to solve our purpose. The main Class MyClass can call the constructor of the MakeFinalClass as they are friend classes.One thing we have to notice, that the MakeFinalClass is also a virtual base class. We will make ...

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Hiding of all overloaded methods in base class in C++

Nishtha Thakur
Nishtha Thakur
Updated on 30-Jul-2019 624 Views

In C++, we can use the function overloading techniques. But if some base class has one method in overloaded form (different function signature with the same name), and the derived class redefines one of the function which is present inside the base, then all of the overloaded version of that function will be hidden from the derived class.Let us see one example to get the clear idea.Example#include using namespace std; class MyBaseClass {    public:       void my_function() {          cout

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Fesetround() and fegetround() in C++

Anvi Jain
Anvi Jain
Updated on 30-Jul-2019 157 Views

Here we will see the fesetround() and fegetround() method in C++. These methods can be found in the cfenv library.The fesetround() method is used to set the specified floating point rounding direction to the current rounding direction. This is used with rint(), nearbyint() and some other rounding functions in C++.The syntax is like below −int fesetround(int round);The round can be among these FE_TONEAREST, FE_DOWNWARD, FE_UPWARD etc. This function returns 0 when rounding direction is successfully applied to the required manner.Example#include #include #include using namespace std; main() {    double x = 4.7, ans;    fesetround(FE_TONEAREST); //round to ...

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Listing modified, old and newly created files on Linux using C++

George John
George John
Updated on 30-Jul-2019 340 Views

Here we will see how to list the modified files and old and newly created files on Linux platform using C++ program.The task is very simple. We can use the Linux shell command to get the files in desired order. The ls –l command is used to get all of the files in long listing format. Here we will add more options to sort them based on time. (Ascending and Descending). The –t command is used to sort based on time, and –r can be added to reverse the sequence.The command will be like below:ls –lt ls –ltrWe will use ...

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Template Specialization in C++

Chandu yadav
Chandu yadav
Updated on 30-Jul-2019 988 Views

In C++, the templates are used to create generalized functions and classes. So we can use any type of data like int, char, float, or some user defined data also using templates.In this section, we will see how to use the template specialization. So now we can define some generalized template for different types of data. And some special template function for special type of data. Let us see some example to get better idea.Example Code#include using namespace std; template void my_function(T x) {    cout

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How do inline variables work in C++/C++17?

Chandu yadav
Chandu yadav
Updated on 30-Jul-2019 3K+ Views

In C++, we can use the inline keyword for functions. In C++ 17 version, the inline variable concept has come.The inline variable is allowed to be defined in multiple translation units. It also follows the one definition rule. If this is defined more than one time, the compiler merges them all into a single object in final program.In C++ (before C++17 version), we cannot initialize the value of static variables directly in the class. We have to define them outside of the class.Example Code#include using namespace std; class MyClass {    public:       MyClass() {       ...

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