C++ Articles - Page 616 of 717

We have seen falling matrix scene in different films etc. Here we will see how to write a C++ program to do like that.To solve this problem, we have to care about these steps.Define width of the matrixTwo successive characters may or may not have same amount of gap between themA certain amount of delay between printing each line to visualize the falling effect.Example#include #include #include #include #include #include const int wd = 70; //set the width of the matrix window const int flipsPerLine =5; //five flips for the boolean array 'alternate' const int sleepTime = 50; //it will take ... Read More

Here we will see three functions. These functions are Rint(), rintf() and the rintl(). These functions are used to convert floating point values into rounded format.The rint() FunctionThis function is used for rounding floating point value to integer. The syntax is like below. If the result is outside of return type, the domain error may occur. When the argument is 0 or infinity, then it will return unmodifiedfloat rint(float argument) double rint(double argument) long double rint(long double argument)Example#include #include using namespace std; main() {    double a, b, x, y;    x = 53.26;    y = 53.86; ... Read More

In this section, we will see how to use the catch block for exception handling and the type conversion in C++.At first, let us see a code, and we will see what will be the output, and how they are generating.Example#include using namespace std; int main() {    try{       throw 'a';    }    catch(int a) {       cout

Here we will see how to start some third-party application like notepad or anything using C++ program. This program is very simple, we can use command prompt command to do this task.We will pass the application name inside the system() function. This will open it accordingly.Example#include using namespace std; int main() {    cout >> "Opening Nodepad.exe" >> endl;    system("notepad.exe"); }Output

Here we will see how to check how many digits are there in an integer in C++. At first we will see the traditional rule, then a shorter method and finally another approach to find the digit count. For example, given a single integer (which can be positive, negative, or zero): //Example 1 Input: 12345 Output: 5 //Example 2 Input: -789 Output: 3 Note: The minus sign (if present) is not counted as a digit. Determining how many digits there are in an integerWe can count the number of digits in an integer using different methods ... Read More

Here we will see how to get the memory usage statistics under Linux environment using C++.We can get all of the details from “/proc/self/stat” folder. Here we are taking the virtual memory status, and the resident set size.Example#include #include #include #include #include using namespace std; void mem_usage(double& vm_usage, double& resident_set) {    vm_usage = 0.0;    resident_set = 0.0;    ifstream stat_stream("/proc/self/stat", ios_base::in); //get info from proc    directory    //create some variables to get info    string pid, comm, state, ppid, pgrp, session, tty_nr;    string tpgid, flags, minflt, cminflt, majflt, cmajflt;    string ... Read More

In C++, we can overload the functions. But sometimes the overloading is not done. In this section, we will see what are the different cases, in which we cannot overload the functions.When function signatures are same, only the return type is different, then we cannot overload the function.int my_func() {    return 5; } char my_func() {    return 'd'; }When the member functions have the same name and same parameter list in a class, then they cannot be overloaded.class My_Class{    static void func(int x) {       //Something    }    void func(int x) {     ... 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 pseudorandom number generator algorithm. This function returns nothing.To get the number ... Read More

In C++11, the lambda was introduced. Lambdas are basically a part of, that can be nested inside other function call statements. By combining lambda expressions with the auto keyword, they can be used later.In C++14, these lambda expressions are improved. Here we can get the generalized or generic lambda. For example, if we want to create a lambda, that can add integers, add numbers, also concatenate strings, then we have to use this generalized lambda.Syntax of the lambda expression is looking like this −[](auto x, auto y) { return x + y; }Let us see one example to get the ... Read More

In C++11, we can get the random library to generate random numbers. Here we have used random_device once to seed the random number generator object called mt. This random_device is slower than the mt19937, but we do not need to seed it. It requests for random data to the operating system.Example #include #include using namespace std; int main() {    random_device rd;    mt19937 mt(rd());    uniform_real_distribution dist(20.0, 22.0); //range is 20 to 22    for (int i=0; i> dist(mt) >> endl; }Output21.5311 21.7195 21.0961 21.9679 21.197 21.2989 20.6333 20.441 20.7124 20.2654 21.1877 20.4824 20.0575 20.9432 21.222 21.162 21.1029 20.2253 21.5669 20.3357