C - Array's

Array - What are Array's?

• An array is a collection of similar data type
• Elements occupy consecutive memory locations (addresses)
• First element with lowest address and the last element with highest address
• Elements are indexed from 0 to SIZE – 1.  Example : 5 elements array (say array[5]) will be indexed from 0 to 4
• Accessing out of range array elements would be “illegal access” Example : Do not access elements array[-1] and array[SIZE]
• Array size can't be altered at run time

Array Reading:

#include <stdio.h>
int main()
{
int array[5] = {1, 2, 3, 4, 5};
int index;
index = 0;
do
{
printf(“Index %d has Element %d\n ”, index, array[index]);
index++;
} while (index < 5);
return 0;
}

Array Sorting:

#include <stdio.h>
int main()
{
int array[5];
int index;
for (index = 0; index < 5; index++)
{
scanf(“%d”, &num_array[index]);
}
    return 0;
}

Array Initialising:

#include <stdio.h>
int main()
{
int array1[5] = {1, 2, 3, 4, 5};
int array2[5] = {1, 2};
int array3[] = {1, 2};
int array4[]; /* Invalid */
printf(“ %u\n ”, sizeof (array1));
printf(“ %u\n ”, sizeof (array2));
printf(“ %u\n ”, sizeof (array3));
return 0;
}