# Explain scope rules related to the functions in C language

CServer Side ProgrammingProgramming

Scope rules are related to the following factors −

• Accessibility of a variables.
• Period of existence of a variable.
• Boundary of usage of variables.

## Scope rules related to functions are as follows

• Function which is a self-contained block that performs a particular task.

• Variables that are declared within the function body are called local variables.

• These variables only exist inside the specific function that creates them. They are unknown to other functions and to the main functions too.

• The existence of local variables ends when the function completes its specific task and returns to the calling point.

## Example 1

Following is the C program for scope rules related to functions

#include<stdio.h>
main ( ){
int a=10, b = 20;
printf ("before swapping a=%d, b=%d", a,b);
swap (a,b);
printf ("after swapping a=%d, b=%d", a,b);
}
swap (int a, int b){
int c;
c=a;
a=b;
b=c;
}

## Output

The output is stated below −

Before swapping a=10, b=20
After swapping a = 10, b=20
• Variables that are declared outside the function body are called global variables.

• These variables are accessible by any of the functions.

## Example 2

Here is another C program for scope rules related to functions

include<stdio.h>
int a=10, b = 20;
main(){
printf ("before swapping a=%d, b=%d", a,b);
swap ( );
printf ("after swapping a=%d, b=%d", a,b);
}
swap ( ){
int c;
c=a;
a=b;
b=c;
}

## Output

The output is stated below −

Before swapping a = 10, b =20
After swapping a = 20, b = 10
Published on 11-Mar-2021 12:28:46