# Initialising byte array with Decimal, Octal and Hexadecimal numbers in C

Here, we are going to learn how to declare byte array and initialise array with decimal, octal and hexadecimal numbers in C language.
Submitted by IncludeHelp, on September 06, 2018

## byte array in C

In C programming language, an unsigned char type can be used to declare byte array in C programming language. An unsigned char can contain a value from 0 to 255, which is the value of a byte.

In this example, we are declaring 3 arrays – arr1, arr2, and arr3, arr1 is initialising with decimal elements, arr2 is initialising with octal numbers and arr3 is initialising with hexadecimal numbers.

Example:

```#include <stdio.h>

int main()
{
//declaring array, initialising with decimal values
unsigned char arr1[]={10, 20, 30, 40, 50};
//declaring array, initialising with octal values
unsigned char arr2[]={010, 077, 023, 045, 057};
//declaring array, initialising with hexadecimal values
unsigned char arr3[]={0x10, 0xAA, 0x67, 0xA1, 0xFF};
int i;

//printing the numbers
printf("arr1...\n");
for(i=0; i<5; i++)
printf("%d ",arr1[i]);
printf("\n");

//printing the numbers
printf("arr2...\n");
for(i=0; i<5; i++)
printf("%o ",arr2[i]);
printf("\n");

//printing the numbers
printf("arr3...\n");
for(i=0; i<5; i++)
printf("%X ",arr3[i]);
printf("\n");

return 0;
}
```

Output

```arr1...
10 20 30 40 50
arr2...
10 77 23 45 57
arr3...
10 AA 67 A1 FF
```