Finding the length of an array using this function

Question

Can anyone explain to me how to call the following function to find the length of an array? Thanks!

int len(char* s)
{
    int k = 0;
    while (*s)
    {
        k++;
        s++;
    }
    return k;
}

How to call that function? Write len(s) where s is a pointer to a char array. — flogram_dev
– flogram_dev, Commented Feb 7, 2015 at 13:05
This function can't tell you the length of an array. It looks like a (bad) substitute for strlen() though, which gives you the length of a C-style string. Using C-style strings is the first thing to get rid of when learning C++ though... — Ulrich Eckhardt
– Ulrich Eckhardt, Commented Feb 7, 2015 at 13:19

πάντα ῥεῖ · Accepted Answer · 2015-02-07 13:05:42Z

1

"can anyone explain me how to call this function to find the length of an array?"

You can call it like this

char* array = "Hello World!";
int length = len(array);

answered Feb 7, 2015 at 13:05

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Comments

Sergey Kalinichenko · Accepted Answer · 2015-02-07 13:05:49Z

1

This function will not help you find the length of just any array - only some very specific ones:

In C arrays like that are created when you do this:

char array[] = "12345";

This is a six-element character array, with five initial elements occupied by non-zero character codes, and the sixth element occupied by zero.

Now the algorithm becomes clear: count elements until you hit zero, include zero in the count, and return the result:

char array[] = "12345";
int res = len(array);

answered Feb 7, 2015 at 13:05

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