Ufdjrw

I am trying to convert a a const.char to a lowercase version of that word. Here is the code I currently I have:

int i=0;
char DuplicateArray[45];
int sizevalue=0;
Node* NodePointer=NULL;
unsigned int hashval=0;
int counter=0;
sizevalue=strlen (word);

strncpy(&DuplicateArray[counter], word,sizevalue);//word is the const char pointer.
DuplicateArray[sizevalue+1] = '';
hashval=hash(DuplicateArray);//function I call to determine hash value
while ( DuplicateArray[i] != '' )

 DuplicateArray[i] = tolower(DuplicateArray[i]); 
 i++;

With this code I have, however, I am not able to make the characters in the array lower cased. Does anyone have any idea on what I am doing wrong?

My guess is that you're either misunderstanding arrays and the & and [] operators, or the other various "small" mistakes in your code (that all result in UB as far as I can tell) make your program misbehave. This works:

#include <string.h>
#include <stdio.h>

int main()

 const char* uppercase = "UpPeRcAsE";

 char duplicateArray[45];
 int uppercaseSize = strlen(uppercase);

 // copy uppercase into duplicateArray
 strncpy(duplicateArray, uppercase, uppercaseSize);

 duplicateArray[uppercaseSize] = '';
 int i = 0;
 while (duplicateArray[i] != '')
 
 duplicateArray[i] = tolower(duplicateArray[i]); 
 i++;
 

 printf("Before: %s, after: %sn", uppercase, duplicateArray);

 return 0;

If the encoding is Ascii, do it in binary. The difference is in bit 6, which is 0 in uppercase letters and 1 in lowercase letters. You can easily find do it by subtracting 32 in decimal, or just flip the sixth bit. For example, character A is 1000001 (0x41) and character a is 1100001 (0x61).

use this

#include <stdio.h>
#include <ctype.h>

void dotolower(const char *cstr)

 char *str = (char*)cstr;

 while (*str) 
 *str = tolower(*str);
 ++str;
 


int main()

 char mystr[] = "HELLO";
 dotolower(mystr);
 puts(mystr); 

 return 0;

as an example