Array Example in C
- An array is a collection of similar types of data elements arranged in such a way that any number of values can be assigned to it.
- It can store values that can be any number, but it must be of the same datatype. For example, if you want to store hundred (100) values of the same data type, they can be stored in a single array.
- The data type that we declare in an array can be of any type like Char, Int, double, Float, or a String.
How to declare an Array?
Format for declaring an Array is
datatype NameoftheArray[SizeoftheArray];For example: -
1.int data [100];
2. char data [5];
3.double data [10];
4.float data [15];
In the above examples, in first one we see that the (100) elements of the same data type, i.e., integer(int), are stored in a single array.
In the second one, five elements of the character(char) data type are stored in a single array.
In the same way, the double values and the float values are stored in a single array.
How to access the elements of Array?
- Array elements are accessed by indices.
- The Assessing of Array elements in the indices starts with 0, not with 1.
- If you stored an element in an array as mentioned above, the first element would be stored in the 0th index in arr[0]. The second element will be stored in the 1st index arr[1], and so on.
- If you want to initialize an array and store the values in the compile time, you can store the elements in an array as n, i.e., arr[n].
- If the address of the first index that is stored in array arr[0] is 500, then the address of the second index stored in arr[1] will be 502, and the third index is 504, and so on. This is due to the size of the type of data type Int being 2 Bytes.
- The address of the adjacent array element is increased depending upon the data type that is used in the array, like Int (2 Bytes), Float (4 bytes), double (16 bytes), etc.
Initialization of elements of an Array
The initialization of any array elements is done during the declaration of the array in the code.
The initialization of the array can be in any order. There is no rule that there should be an ascending or descending order. They can be in a zigzag manner.
Ex: -
int arr[10] = {1,54,19,76,24,98,26,7,13,77};
float arr[5] = {5.6, 4.9, 3.7, 9.2, 0.5};
An array can also be initialized without mentioning the size of the array, Only, if you have your own data elements.
Ex: -
int arr[] = {1,54,19,76,24,98,26,7,13,77};
float arr[5] = {5.6, 4.9, 3.7, 9.2, 0.5};
If you want to set the number of data elements in the compile time, then you can give the size of an array as n and run the code.
Input:
int arr[n] = new array;
Input and Output
Here's how you can take input from the user and store it in an array element.
taking the input and storing it in the 3rd position:
scanf("%d", &arr[2]);
taking the input and storing it in the ithe position:
scanf("%d", &arr[i-1]);
Here's how you can print an individual element of an array.
- printing the first element of the array
printf("%d", arr[0]);
- printing the third element of the array
printf("%d", arr[2]);
- printing ith element of the array
printf("%d", arr[i-1]);
Examples of Array in C
Example-1: For INTEGER datatype
#include <stdio.h>
void main()
{
int arr[10];
int i;
printf("\nRead and Print elements of an array:\n");
printf("--------------\n");
printf("Input 10 Elements in the array :\n");
for(i=0; i<10; i++)
{
printf(" %d : ",i);
scanf("%d", &arr[i]);
}
printf("\nElements in array are: ");
for(i=0; i<10; i++)
{
printf("%d ", arr[i]);
}
printf("\n");
}Output:-
Read and Print elements of an array:
---------------
Input 10 elements in the array :
0: 1
1: 1
2: 2
3 : 3
4: 4
5: 5
6: 6
7: 7
8: 8
9: 9
Elements in array are: 1 1 2 3 4 5 6 7 8 9
Example: 2 For FLOAT datatype
#include<stdio.h>
void main()
{
float arr[10];
float i;
printf("\n\nRead and Print elements of an array:\n");
printf("--------------\n");
printf("Input 10 elements in the array :\n");
for(i=0; i<10; i++)
{
printf("%d : ",i);
scanf("%d", &arr[i]);
}
printf("\nElements in array are: ");
for(i=0; i<10; i++)
{
printf("%d ", arr[i]);
}
printf("\n");
}
Output:-
Read and Print elements of an array:
---------------
Input 10 elements in the array :
0: 1.1
1: 7.5
2: 9.7
3: 8.9
4: 9.3
5: 5.5
6: 1.0
7: 3.3
8: 4.9
9: 6.1
Elements in array are: 1.1, 7.5, 9.7, 8.9, 9.3, 5.5, 1.0, 3.3, 4.9, 6.1 Example Code to reverse an Array
#include <stdio.h>
void main ()
{
int i,n,a[50];
printf("\n Input a number of values inside array and displaying it in the reverse order:\n");
printf("----------------\n");
printf("Input the number of elements :");
scanf("%d",&n);
printf("Input %d number of elements :\n",n);
for(i=0;i<n;i++)
{
printf("%d : ",i);
scanf("%d",&a[i]);
}
printf("\nThe values that are stored inside the array are: \n");
for(i=0;i<n;i++)
{
printf("% 5d",a[i]);
}
printf("\n\nThe values that are stored inside the array reverse are :\n");
for(i=n-1;i>=0;i--)
{
printf("% 5d",a[i]);
}
printf("\n");
} Output:
Input a number of values inside array and displaying it in the reverse order:
----------------
Input the number of elements :3
Input 3 number of elements :
0 : 2
1 : 5
2 : 7
The values that are stored inside the array are:
2 5 7
The values that are stored inside the array reverse are :
7 5 2