wcslen, wcsnlen_s
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                    | Defined in header  <wchar.h> | ||
| size_t wcslen( const wchar_t *str ); | (1) | (since C95) | 
| (2) | (since C11) | |
1) Returns the length of a wide string, that is the number of non-null wide characters that precede the terminating null wide character.
2) Same as (1), except that the function returns zero if 
str is a null pointer and returns strsz if the null wide character was not found in the first strsz wide characters of src
- As all bounds-checked functions, wcsnlen_sis only guaranteed to be available if __STDC_LIB_EXT1__ is defined by the implementation and if the user defines __STDC_WANT_LIB_EXT1__ to the integer constant 1 before includingwchar.h.
| Contents | 
[edit] Parameters
| str | - | pointer to the null-terminated wide string to be examined | 
| strsz | - | maximum number of wide characters to examine | 
[edit] Return value
1) The length of the null-terminated wide string 
str.2) The length of the null-terminated wide string 
str on success, zero if str is a null  pointer, strsz if the null wide character was not found.[edit] Notes
strnlen_s and wcsnlen_s are the only bounds-checked functions that do not invoke the runtime constraints handler. They are pure utility functions used to provide limited support for non-null terminated strings.
[edit] Example
Run this code
Output:
without null character: 50 with null character: 51
[edit] References
- C11 standard (ISO/IEC 9899:2011):
- 7.29.4.6.1 The wcslen function (p: 439)
 
- K.3.9.2.4.1 The wcsnlen_s function (p: 646-647)
 
- C99 standard (ISO/IEC 9899:1999):
- 7.24.4.6.1 The wcslen function (p: 385)
 
[edit] See also
| (C11) | returns the length of a given string (function) | 
| C++ documentation for wcslen | |


