CODEWITHSUNDEEP
cstringoverwrite
goe
goe

Reputation: 5425

What's the best way to reset a char[] in C?

I use a string:

char    word[100];

I add some chars to each position starting at 0. But then I need be able to clear all those positions so that I can start add new characters starting at 0.

If I don't do that then if the second string is shorten then the first one I end up having extra characters from the first string when adding the second one since I don't overwrite them.

Upvotes: 9

Views: 50807

Answers (4)

user82238
user82238

Reputation:

You could assign a null terminator to the first position of the char array.

*word = '\0';

Upvotes: 1

user3446207
user3446207

Reputation:

strcpy(word,"") can also be used for this purpose.

Upvotes: 5

Mehrdad Afshari
Mehrdad Afshari

Reputation: 422132

If you want to zero out the whole array, you can:

memset(word, 0, sizeof(word));

Upvotes: 24

Heath Hunnicutt
Heath Hunnicutt

Reputation: 19477

You don't need to clear them if you are using C-style zero-terminated strings. You only need to set the element after the final character in the string to NUL ('\0').

For example,

char buffer[30] = { 'H', 'i', ' ', 'T', 'h', 'e', 'r', 'e', 0 };
// or, similarly:
// char buffer[30] = "Hi There";  // either example will work here.

printf("%s", buffer);
buffer[2] = '\0';
printf("%s", buffer)

will output

Hi There
Hi

even though it is still true that buffer[3] == 'T'.

Upvotes: 12

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