What do you mean by static memory allocation in C programming?

Memory can be allocated in the following two ways −

Static Memory Allocation

Static variable defines in one block of allocated space, of a fixed size. Once it is allocated, it can never be freed.

Memory is allocated for the declared variable in the program.

• The address can be obtained by using ‘&’ operator and can be assigned to a pointer.

• The memory is allocated during compile time.

• It uses stack for maintaining the static allocation of memory.

• In this allocation, once the memory is allocated, the memory size cannot change.

• It is less efficient.

The final size of a variable is decided before running the program, it will be called as static memory allocation. It is also called compile-time memory allocation.

We can't change the size of a variable which is allocated at compile-time.

Example 1

Static memory allocation is generally used for an array. Let’s take an example program on arrays −

 Live Demo

#include<stdio.h> main (){    int a[5] = {10,20,30,40,50};    int i;    printf (“Elements of the array are”);    for ( i=0; i<5; i++)       printf (“%d, a[i]); }

Output

Elements of the array are 1020304050

Example 2

Let’s consider another example to calculate sum and product of all elements in an array −

 Live Demo

#include<stdio.h> void main(){    //Declaring the array - run time//    int array[5]={10,20,30,40,50};    int i,sum=0,product=1;    //Reading elements into the array//    //For loop//    for(i=0;i<5;i++){       //Calculating sum and product, printing output//       sum=sum+array[i];       product=product*array[i];    }    //Displaying sum and product//    printf("Sum of elements in the array is : %d
",sum);    printf("Product of elements in the array is : %d
",product); }

Output

Sum of elements in the array is : 150 Product of elements in the array is : 12000000