How to remove these warning when erasing a c string

How can I remove these warnings?

   char foo[10], msg2[100]; 
   int k;
   for (开发者_运维百科k = 0; foo[k] != NULL; k++) //comparison between pointer and integer
       msg2[k] = NULL; //assignment makes integer from pointer without a cast

Thanks.

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   int k;
   for (k = 0; foo[k] != '\0'; k++)
       msg2[k] = '\0';

Assign an integer to an integer variable, instead of a pointer. NULL is a pointer. It is usually defined as:

((void *) 0)

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The warning is right, your usage of NULL is wrong.

NULL was meant for pointers, not for string nul-terminator.

Use zero instead of NULL in your code, in BOTH places. If you want a special zero, you may use '\0', but that;s redundant.

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*foo = 0;

To "Erase" a C style string, all you need to do is set the first byte to 0.