Explain scope of a variable in C language.
Storage classes specify the scope, lifetime and binding of variables.
To fully define a variable, one needs to mention not only its ‘type’ but also its storage class.
A variable name identifies some physical location within computer memory, where a collection of bits are allocated for storing values of variable.
Storage class tells us the following factors −
- Where the variable is stored (in memory or cpu register)?
- What will be the initial value of variable, if nothing is initialized?
- What is the scope of variable (where it can be accessed)?
- What is the life of a variable?
Scope
Scope defines the visibility of an object. It defines where an object can be accessed.
The scope variable is local or global
- The variable defined within the block has local scope. They are visible only to the block in which they are defined.
- The variable defined in global area is visible from their definition until the end of program. It is visible everywhere in program.
Example
Following is the C program for the scope of a variable −
#include<stdio.h>
int c= 30; /* global area */
main ( ) {
int a = 10; //local scope//
printf ("a=%d,c=%d"a,c);
fun ( );
}
fun ( ){
printf ("c=%d",c); //global variable
}Output
When the above program is executed, it produces the following output −
a =10, c = 30
c = 30
Example
Following is the C program for the local and global variables −
Live Demo
#include<stdio.h>
int a,b;
a=1,b=2;
main() {
int c,d;
printf("enter c and d values:");
scanf("%d%d",&c,&d);
c=c+d; //local variables
b=a*b; //global variables
printf("c value is:%d\n",c);
printf("b value is:%d\n",b);
}Output
When the above program is executed, it produces the following output −
enter c and d values:4 7
c value is:11
b value is:2
Published on 25-Mar-2021 08:07:21
