The Tale of Two Variables: Auto and Static

#include<stdio.h>

void increment (); //function decalaration

    int main(){
        increment (); // function call 3 times 
        increment();
        increment();
        return 0;
    }
    void increment (){ // function definition   
        auto int i=1;
        static int j=1;
        i=i+1;
        j=j+1;
        printf("%d %d\n",i,j);
    }

Imagine you're working as a cashier at a store, helping customers with their purchases. Here's how auto and static variables would play out:

1. Auto (The Short-Term Helper):

• An auto variable is like a temporary helper you hire for each customer.

• When a new customer arrives (function call), you create a new helper (variable) named i.

• You initialize i to 1, giving them a starting point (initializing the variable).

• You increment i by 1 to track the number of items the customer buys (incrementing the variable).

• You tell the customer the total items (printing i).

• Once the customer leaves, you dismiss the temporary helper i. They're no longer needed.

• This happens for every new customer (function call). So, each customer gets a fresh i that starts at 1 and goes up to 2.

2. Static (The Persistent Assistant):

• A static variable is like a seasoned employee who stays on long-term.

• The first time a customer arrives (function call), you hire a new employee, j.

• You initialize j to 1 to keep track of the total customers served (initializing the variable).

• Every subsequent customer gets the same j employee, who remembers the previous number served.

• You increment j by 1 for each new customer.

• You tell the customer their total number (printing j).

• Unlike the temporary helper, j stays on even after the customer leaves (function ends). This means j remembers the total count between customers.

Why the Different Outputs?

• Because auto variables are like temporary helpers, they start fresh every time (always 2 for each customer).

• static variables, like the persistent employee, keep track of the overall count, leading to an increasing value (j keeps increasing).

I hope this story clarifies the difference between auto and static variables!