C++ Articles - Page 627 of 717

The Copy Elision is also known as the Copy Omission. This is one of the compiler optimization technique. It avoids the unnecessary copying of objects. Almost any current compiler uses this Copy Elision technique.Let us see how it works by the help of one example code:Example Code#include using namespace std; class MyClass {    public:       MyClass(const char* str = "\0") {  //default constructor          cout

It is possible to pass some values from the command line to your C++ programs when they are executed. These values are called command line arguments and many times they are important for your program especially when you want to control your program from outside instead of hard-coding those values inside the code.The command line arguments are handled using main() function arguments where argc refers to the number of arguments passed, and argv[] is a pointer array which points to each argument passed to the program. Following is a simple example which checks if there is any argument supplied from ... Read More

In C/C++, the expression c = a++ + b indicates that the current value of a is added to b, and the result is assigned to c. After this assignment, a is incremented by 1 (post-increment), which means the increment of a happens after its value is used in the expression. Well, let a and b initialize with 2 and 5, respectively. This expression can be taken as two different types. c = (a++) + b c = a + (++b) The above two expressions contain both post and pre-increment ... Read More

The effective result of i++ and ++i are same. The only difference is that the i++ increases the value of i after assigning it, and for ++i, it increases the value first, then assigns its value. We can see the difference in the following code.Example Code#include using namespace std; int main() {    int x = 3, y, z;    y = x++;    z = ++x;    cout

In this article, we will explore the purpose of using function prototypes in C or C++. What are Function Prototypes? The function prototypes tell the compiler about the number of arguments and the required data types of function parameters; they also tell the compiler about the return type of the function. With this information, the compiler cross-checks the function signatures before calling it. If the function prototypes are not mentioned, then the program may be compiled with some warnings and sometimes generate some strange output. Purpose of a Function Prototype When a function is called before it is defined, and ... Read More

In C or C++, we cannot return multiple values from a function directly. In this Article, we will see how to use some trick to return more than one value from a function. Returning Multiple Values from a Function We can return multiple values from a function by using the method. Below is the list of methods that are used to return multiple values from a function in C/C++: Using Pointers Using Structures Using Arrays Returning Multiple Values Using Pointers Pass the arguments by their addresses ... Read More

Let us see how to generate random numbers using C++. Here we are generating a random number in range 0 to some value. (In this program the max value is 100).To perform this operation we are using the srand() function. This is in the C library. The function void srand(unsigned int seed) seeds the random number generator used by the function rand.The declaration of srand() is like below:void srand(unsigned int seed)It takes a parameter called seed. This is an integer value to be used as seed by the pseudo-random number generator algorithm. This function returns nothing.To get the number we ... Read More

The Pi is a special mathematical value, approximately 3.14159, that is often used in calculations related to circles and geometry. In C++, we need to understand how to access and use this constant in our programs. In this article, we will show how to use the PI constant in a C++ program. The PI constant is available in the cmath header file. We will explain how to use PI to calculate values like the area or circumference of a circle. How to Use Pi in C++ There are multiple ways to use the Pi constant in C++. ... Read More

In this article we will see how to use the namespace in C++ code.Consider a situation, when we have two persons with the same name, Zara, in the same class. Whenever we need to differentiate them definitely we would have to use some additional information along with their name, like either the area, if they live in different area or their mother’s or father’s name, etc.Same situation can arise in your C++ applications. For example, you might be writing some code that has a function called xyz() and there is another library available which is also having same function xyz(). ... Read More

In this article, we will learn how to pass command line parameters in C++. The command line argument is a parameter that is passed to a program when it is invoked by the command line or terminal. Parsing Command Line Parameters in C++ In C++, we can pass the command line argument using the argc and argv[] parameters that are passed to the main function. Where argc refers to the number of arguments passed, and argv[] is a pointer array that points to each argument passed to the program. We can use loops to iterate and parse the command line ... Read More