C Tutorial/Memory/Memory Allocation
Memory Allocation
- The functions for allocation of memory: malloc, relloc, and calloc.
- The functions return the pointers to void, which can be typecast to any data type.
- These functions take the input as the size of memory requirement.
<source lang="cpp">#include <stdio.h>
- include <malloc.h>
main(){
int *base;
int i,j;
int cnt=0;
int sum=0;
printf("how many integers you have to store \n");
scanf("%d",&cnt);
base = (int *)malloc(cnt * sizeof(int));
printf("the base of allocation is %16lu \n",base);
if(!base)
printf("unable to allocate size \n");
else {
for(j=0;j<cnt;j++)
*(base+j)=5;
}
sum = 0;
for(j=0;j<cnt;j++)
sum = sum + *(base+j);
printf("total sum is %d\n",sum);
free(base);
printf("the base of allocation is %16lu \n",base);
base = (int *)malloc(cnt * sizeof(int));
printf("the base of allocation is %16lu \n",base);
base = (int *)malloc(cnt * sizeof(int));
printf("the base of allocation is %16lu \n",base);
base = (int *)calloc(10,2);
printf("the base of allocation is %16lu \n",base);
}</source>
how many integers you have to store 1234 the base of allocation is 4016352 total sum is 6170 the base of allocation is 4016352 the base of allocation is 4016352 the base of allocation is 4021296 the base of allocation is 4007120
