There are two ways available to access value associated with a key in a dictionary collection object. The dictionary class method get() takes key as argument and returns value. >>> d1 = {'name': 'Ravi', 'age': 23, 'marks': 56} >>> d1.get('age') 23 Another way is to use key inside square brackets in front of dictionary object >>> d1 = {'name': 'Ravi', 'age': 23, 'marks': 56} >>> d1['age'] 23

In Python, objects are instances of classes containing attributes and methods, while dictionaries are collections of key-value pairs. We can obtain a dictionary from an object's fields - Using __dict__ Using vars() Using __dict__ You can access an object's attributes as a dictionary using its _dict_ attribute. In Python, every object has a _dict_ attribute that stores the object's attributes and their values as a dictionary (key-value pairs). Example In this example, we have defined a class Company with attributes Companyname and Location, and created ... Read More

In this article, we will show you how to convert a python dictionary to a list. Below are the methods to accomplish this task: Using list & items() Method Using keys() Method Using values() Method Using List Comprehension Using Zip() Function Using map() Function Using for loop & items() Method Dictionaries are Python's version of an associative array data structure. A dictionary is a collection of key-value pairs. Each key pair is represented by a key pair and its associated value. A dictionary is defined by a list of key-value pairs enclosed in curly braces and ... Read More

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

In C++, the scope defines the region within which a variable can be accessed. So, if broadly speaking, there are three main places where variables can be declared and accessed: Inside a function or a block, which are called local variables. In the definition of function parameters, which are called formal parameters. Outside of all functions, which are called global variables. Local Variables Local variables are the variables that are defined inside a function, method, or block of code within curly braces {}. These variables cannot be ... 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

The variables, which are declared inside a function, block or method are known as local variables in C++. Their scope is limited to that function or block and can be accessed and used only within the area or scope they are defined. You cannot access or use them outside their scope. This is mainly used to prevent conflicts with other variables in other parts of the program and to efficiently manage memory. Key Characteristics of Local Variables Scope Limited : These variables are declared inside block or scope (usually {}) and are only visible and used ... Read More

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