auto Storage Class

2. extern Storage Class

The auto storage class is the default class of all the variables declared inside a block. The auto stands for automatic and all the local variables that are declared in a block automatically belong to this class.

Properties of auto Storage Class Objects

Scope: Local
Default Value: Garbage Value
Memory Location: RAM
Lifetime: Till the end of its scope

Example of auto Storage Class

C++

// C++ Program to illustrate the auto storage class
// variables
#include <iostream>
using namespace std;
 
void autoStorageClass()
{
 
    cout << "Demonstrating auto class\n";
 
    // Declaring an auto variable
    int a = 32;
    float b = 3.2;
    char* c = "w3wiki";
    char d = 'G';
 
    // printing the auto variables
    cout << a << " \n";
    cout << b << " \n";
    cout << c << " \n";
    cout << d << " \n";
}
 
int main()
{
 
    // To demonstrate auto Storage Class
    autoStorageClass();
 
    return 0;
}

Output

Demonstrating auto class
32 
3.2 
w3wiki 
G

Note: Earlier in C++, we could use the auto keyword to declare the auto variables explicitly but after C++11, the meaning of auto keyword is changed and we could no longer use it to define the auto variables.

Storage Classes in C++ with Examples

C++ Storage Classes are used to describe the characteristics of a variable/function. It determines the lifetime, visibility, default value, and storage location which helps us to trace the existence of a particular variable during the runtime of a program. Storage class specifiers are used to specify the storage class for a variable.

Syntax

To specify the storage class for a variable, the following syntax is to be followed:

storage_class var_data_type var_name;

C++ uses 6 storage classes, which are as follows:

auto Storage Class
register Storage Class
extern Storage Class
static Storage Class
mutable Storage Class
thread_local Storage Class

Below is a detailed explanation of each storage class:

Tags:

#Storage Classes and Type Qualifiers #C++ #Misc #CPP #Misc