I'm trying to write a simple C function to copy the contents of one char array to another using pointer arithmetic. I can't seem to get it working, can you tell me where I'm going wrong?
#include <stdio.h>
#include <stdlib.h>
void copystr(char *, const char *);
int main()
{
char hello[6] = "hello";
const char world[6] = "world";
copystr(&hello, &world);
return 0;
}
void copystr(char *str1, const char *str2)
{
*str1 = *str2; //copy value of *str2 into *str1
printf("%s %s", *str1, *str2); //print "world" twice
}
Help appreciated, thanks.
EDIT: Here is the working code:
#include <stdio.h>
#include <stdlib.h>
void copystr(char *, const char *);
int main()
{
char hello[6] = "hello";
const char world[6] = "world";
copystr(hello, world);
printf("%s %s", hello, world);
return 0;
}
void copystr(char *str1, const char *str2)
{
/*copy value of *str2 into *str1 character by character*/
while(*str2)
{
*str1 = *str2;
str1++;
str2++;
}
}
You are only copying the first character of the string.
void copystring(char* str1, const char* str2)
{
while(*str2)
{
*str1 = *str2; //copy value of *str2 into *str1
str1++;
str2++;
}
}
and then in main, after calling copystring
printf("%s %s", hello, world); //print "world" twice
But please don't do this! Use strncpy in real life, if working with plain C strings.
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