Question about connecting strings and nul character

There's a string with four numbers and a \0 sign, which's making it needing array size of 5:

Code:

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char string[5] = "1234";

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Now, i want to connect three of these strings with sprintf:

Code:

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sprintf(StringsConnected,"%s%s%s",string,string,string) // probably not the best way, but still ...

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Now, what array size should string StringSonnected have?
- 13, for 123412341234 and \0 or
- 15, for 1234\01234\01234\0 or
- even 16, for 1234\01234\01234\0\0?

Thanks!

> - 13, for 123412341234 and \0 or
Is the correct answer.

Thanks