Found 9326 Articles for Object Oriented Programming

There are two separate concepts here − scope, which determines where a name can be accessed - global and local storage duration, which determines when a variable is created and destroyed - static and auto Scope Local variables can be used only by statements that are inside that function or block of code. Local variables are not known to functions on their own. Example Live Demo #include using namespace std; int main () { // Local variable declaration: int a, b; int c; // actual initialization a = 10; b = 20; c = a + b; cout

A scope is a region of the program and broadly speaking there are three places, where variables can be declared − Inside a function or a block which is called local variables,  In the definition of function parameters which is called formal parameters. Outside of all functions which are called global variables.Local variables can be used only by statements that are inside that function or block of code. Local variables are not known to functions on their own. Example#include using namespace std; int main () {    // Local variable declaration:    int a, b;    int c;    // actual ... Read More

Global variables are defined outside of all the functions, usually on top of the program. The global variables will hold their value throughout the lifetime of your program.A global variable can be accessed by any function. That is, a global variable is available for use throughout your entire program after its declaration. Example#include using namespace std; // Global variable declaration: int g; int main () {    // Local variable declaration:    int a, b;    a = 10;    b = 20;    g = a + b;    cout

Variables that are declared inside a function or block are local variables. They can be used only by statements that are inside that function or block of code. Local variables are not known to functions on their own.ExampleLive Demo#include using namespace std; int main () {    int a, b;    int c;    a = 10;    b = 20;    c = a + b;    cout

There are a total of 95 reserved words in C++. The reserved words of C++ may be conveniently placed into several groups. In the first group, we put those that were also present in the C programming language and have been carried over into C++. There are 32 of these.There are another 30 reserved words that were not in C, are therefore new to C++There are 11 C++ reserved words that are not essential when the standard ASCII character set is being used, but they have been added to provide more readable alternatives for some of the C++ operators, and ... Read More

An lvalue has an address that your program can access. Examples of lvalue expressions include variable names, including const variables, array elements, function calls that return an lvalue reference, bit-fields, unions, and class members. A xvalue expression has no address but can be used to initialize an rvalue reference, which provides access to the expression. Examples include function calls that return an rvalue reference, the array subscript, etc. A glvalue (“generalized” lvalue) is an lvalue or an xvalue. An rvalue (so-called, historically, because rvalues could appear on the right-hand side of an assignment expression) is an xvalue, a temporary object or subobject thereof, ... Read More

An lvalue (locator value) represents an object that occupies some identifiable location in memory (i.e. has an address).rvalues are defined by exclusion. Every expression is either an lvalue or an rvalue, so, an rvalue is an expression that does not represent an object occupying some identifiable location in memory.For example, An assignment expects an lvalue as its left operand, so the following is valid −int i = 10; But this is not: int i; 10 = i;This is because i has an address in memory and is a lvalue. While 10 doesn't have an identifiable memory location and hence is an rvalue. ... Read More

In C the type of a string literal is a char[]. In C++, an ordinary string literal has type 'array of n const char'. For example, The type of the string literal "Hello" is "array of 6 const char". It can, however, be converted to a const char* by array-to-pointer conversion.Note that Array-to-pointer conversion results in a pointer to the first element of the array.

In C++, a character in single quotes is a character literal. It's of type char. For example, 'a' is of type char with a value 97 on an ASCII based system.A character or a string of characters together in double quotes represent a string literal. It's of type const char[] and refers to an array of size length of string + 1. That extra character is there for marking the string's ending.String literals can be arbitrarily long, such as "abcdefg". Character literals almost always contain just a single character. When these are being printed, string literals are printed till the ... Read More

An enumerated type declares an optional type name and a set of zero or more identifiers that can be used as values of the type. Each enumerator is a constant whose type is the enumeration. These are also called as enumerated constants.For example, if you are creating an application that has a fixed number of types for some variable. For example, let's say gender, it can be of three types male, female and others. You can define and use an enum like −#include using namespace std; enum Gender {MALE, FEMALE, OTHERS}; int main() {    Gender gen = Gender.FEMALE;   ... Read More