CODEWITHSUNDEEP
carrays
maxisme
maxisme

Reputation: 4245

How to copy array value to another array

I have two arrays:

char roundNames1[16][25], roundNames2[16 / 2][25];

I then want to copy a result from the first array to the second. I have tried this:

where roundNames1[5] = "hello"

#include <string.h>

printf("First array: %s", roundNames1[5]);
strcpy(roundNames1[5], roundNames2[6]);
printf("Second array: %s", roundNames2[6]);

But this just returns

First array: hello
Second array:

Why is it not working?

Upvotes: 1

Views: 104

Answers (3)

Felix Quehl
Felix Quehl

Reputation: 813

Copy arrays/strings with memcpy

void * memcpy (void * destination, void * source, size_t size)

The memcpy function copies an certain amount of bytes from a source memory location and writes them to a destinaction location. (Documentation)

Example:

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

int main()
{
    char some_array[] = "stackoverflow";

    int memory_amount = sizeof(some_array);
    char *pointer = malloc(memory_amount);
    memcpy(pointer, &some_array, memory_amount);

    printf("%s\n", pointer);

    free(pointer);
    return 0;
}

Output

$ ./a.out 
stackoverflow

Upvotes: 0

bwinata
bwinata

Reputation: 191

strcpy - arguments other way around.

http://www.cplusplus.com/reference/cstring/strcpy/

Upvotes: 1

Vlad from Moscow
Vlad from Moscow

Reputation: 310930

You need to exchange arguments of function strcpy

strcpy( roundNames2[8], roundNames1[5] );

Here is a part pf the function description from the C Standard

7.23.2.3 The strcpy function

Synopsis

1 

#include <string.h>
char *strcpy(char * restrict s1, const char * restrict s2);

Description

2 The strcpy function copies the string pointed to by s2 (including the terminating null character) into the array pointed to by s1. If copying takes place between objects that overlap, the behavior is undefined.

Upvotes: 2

Related Questions