function
<cstring>

strlen

size_t strlen ( const char * str );
Get string length
Returns the length of the C string str.

The length of a C string is determined by the terminating null-character: A C string is as long as the number of characters between the beginning of the string and the terminating null character (without including the terminating null character itself).

This should not be confused with the size of the array that holds the string. For example:

char mystr[100]="test string";

defines an array of characters with a size of 100 chars, but the C string with which mystr has been initialized has a length of only 11 characters. Therefore, while sizeof(mystr) evaluates to 100, strlen(mystr) returns 11.

In C++, char_traits::length implements the same behavior.

Parameters

str
C string.

Return Value

The length of string.

Example

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/* strlen example */
#include <stdio.h>
#include <string.h>

int main ()
{
  char szInput[256];
  printf ("Enter a sentence: ");
  gets (szInput);
  printf ("The sentence entered is %u characters long.\n",(unsigned)strlen(szInput));
  return 0;
}


Output:

Enter sentence: just testing
The sentence entered is 12 characters long.

See also

strcmp
Compare two strings (function )
strchr
Locate first occurrence of character in string (function )
strrchr
Locate last occurrence of character in string (function )