#include <string.h>
#include <stdio.h>
 
int main()
{
 
    const char *word = "UpPeRcAsE";
    
    char DuplicateArray[45];
    int sizevalue = strlen (word);
    
    strncpy(DuplicateArray, word, sizevalue);//word is the const char pointer.
    DuplicateArray[sizevalue] = '\0';
    int i = 0;
    while ( DuplicateArray[i] != '\0' )
    {
        DuplicateArray[i] = tolower(DuplicateArray[i]);    
        i++;
    }
    
    printf("Before: %s, after: %s\n", word, DuplicateArray);
    
    return 0;
}