Merge Two One Dimensional Arrays using C program

/*Program to merge two arrays*/
#include <stdio.h>

/** funtion :   readArray() 
    input   :   arr ( array of integer ), size 
    to read ONE-D integer array from standard input device (keyboard). 
**/
void readArray(int arr[], int size)
{
    int i = 0;

    printf("\nEnter elements : \n");

    for (i = 0; i < size; i++) {
        printf("Enter arr[%d] : ", i);
        scanf("%d", &arr[i]);
    }
}

/** funtion :   printArray() 
    input   :   arr ( array of integer ), size 
    to display ONE-D integer array on standard output device (moniter). 
**/
void printArray(int arr[], int size)
{
    int i = 0;

    printf("\nElements are : ");

    for (i = 0; i < size; i++) {
        printf("\n\tarr[%d] : %d", i, arr[i]);
    }
    printf("\n");
}

void merge(int arr1[], int size1, int arr2[], int size2, int arr3[])
{
    int i = 0, j = 0;

    for (i = 0; i < size1; i++)
        arr3[i] = arr1[i];

    for (i = 5, j = 0; i < size2 + 5; i++, j++)
        arr3[i] = arr2[j];
}

int main()
{
    int arr1[5];
    int arr2[5];
    int arr3[10];

    readArray(arr1, 5);
    readArray(arr2, 5);

    merge(arr1, 5, arr2, 5, arr3);

    printArray(arr3, 10);

    return 0;
}

Output:

    Enter elements : 
    Enter arr[0] : 12 
    Enter arr[1] : 23 
    Enter arr[2] : 34 
    Enter arr[3] : 45 
    Enter arr[4] : 56 

    Enter elements : 
    Enter arr[0] : 11 
    Enter arr[1] : 22 
    Enter arr[2] : 33 
    Enter arr[3] : 44 
    Enter arr[4] : 55 

    Elements are : 
	    arr[0] : 12 
	    arr[1] : 23 
	    arr[2] : 34 
	    arr[3] : 45 
	    arr[4] : 56 
	    arr[5] : 11 
	    arr[6] : 22 
	    arr[7] : 33 
	    arr[8] : 44 
	    arr[9] : 55