9 Declarations [dcl.dcl]

9.4 Initializers [dcl.init]

9.4.3 Character arrays [dcl.init.string]

An array of ordinary character type ([basic.fundamental]), char8_­t array, char16_­t array, char32_­t array, or wchar_­t array can be initialized by an ordinary string literal, UTF-8 string literal, UTF-16 string literal, UTF-32 string literal, or wide string literal, respectively, or by an appropriately-typed string-literal enclosed in braces ([lex.string]).
Successive characters of the value of the string-literal initialize the elements of the array.
[Example 1:
char msg[] = "Syntax error on line %s\n"; shows a character array whose members are initialized with a string-literal.
Note that because '\n' is a single character and because a trailing '\0' is appended, sizeof(msg) is 25.
— end example]
There shall not be more initializers than there are array elements.
[Example 2:
char cv[4] = "asdf"; // error is ill-formed since there is no space for the implied trailing '\0'.
— end example]
If there are fewer initializers than there are array elements, each element not explicitly initialized shall be zero-initialized ([dcl.init]).