How to empty a char array?

Question

Have an array of chars like char members[255]. How can I empty it completely without using a loop?

char members[255]; 

By "empty" I mean that if it had some values stored in it then it should not. For example if I do strcat then old value should not remain

members = "old value";  //empty it efficiently strcat(members,"new"); // should return only new and not "old value new" 

Answer 1

using

  memset(members, 0, 255); 

in general

  memset(members, 0, sizeof members); 

if the array is in scope, or

  memset(members, 0, nMembers * (sizeof members[0]) ); 

if you only have the pointer value, and nMembers is the number of elements in the array.

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EDIT Of course, now the requirement has changed from the generic task of clearing an array to purely resetting a string, memset is overkill and just zeroing the first element suffices (as noted in other answers).

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EDIT In order to use memset, you have to include string.h.

Answer 2

Depends on what you mean by 'empty':

members[0] = '\0';