strlen() returns the string count with the null terminator

Question

normally, strlen() does not count the null terminator at the end of the string. But, below code prints the string count with the null terminator. Can anyone explain me why? Thanks

char str2[100];
printf("\nEnter a string: ");
fgets (str2, sizeof(str2), stdin);
printf("\n%d",strlen(str2));

Answer 1

I am assuming the preceding fgets prompt picked up the newline character.

For example:

You put in apple.

Internally your string was stored as apple\n\0.

strlen then returned 6 for apple + '\n'

Answer 2

The fgets() function accepts the input when a newline character(Enter key when using stdin) is encountered, and the newline character \n is considered a valid character by the function and included in the string copied to your str2.Hence when you pass it as a parameter to strlen() it gives one more than the original number of characters in your string to account for the additional \n character.

If you want the original number of characters or don't want a \n to be added, use the gets() function as it doesn't copy the newline character.And further, you only need to pass the string as argument,no need to pass the stream (stdin) as the default stream for gets() is stdin.

char str2[100];
printf("\nEnter a string: ");
gets(str2);
printf("\n%d",strlen(str2));