Find the length of string in c with just one line of code without using strlen() function?

Question

I want to find if there is any way to find the length of any string in C .
Here's how I did:

#include <stdio.h>
int main()
{
    char s[10] = "hello";
    int i , len = 0;
    for(i = 0; s[i] != '\0'; i++)
    {
        len++
    }
    printf("length of string is: %d" , len);
    return 0;
}

I want to find, if there is any way to get the length of string in just one line of code.

Answer 1

You can just simply do this:

for(len = 0; s[len] != '\0'; len++);

So in just one line of code you will get the length of string stored in len .

Answer 2

You can remove s[len] != '\\0'; comparison to make it shorter:

for(len=0;s[len];len++);

Answer 3

You can call strlen() function to know length of the string in one line. it returns an size value size_t strlen(char*)

Answer 4

just do this:

for(len=0;s[len];len++);

this will store the length in len

Answer 5

If you want only one line, the something like this is also possible:

while (s[len] != '\0') len++;

Which is just another way of doing it, but not most pleasing to look at.

Answer 6

The most minimal version:

#include <stdio.h>

int main(void)
{
  char s[10] = "hello", *p = s;

  while(*p++); /* "counting" here */

  printf("The length of string '%s' is: %td" , s, p - s);
}

It prints:

The length of string 'hello' is: 6

Answer 7

I believe, this should be the shortest version:

for(l=-1;s[++l];);

It's 18 bytes, so it's quite a good code-golf answer. However, I would prefer the more canonical

for(len = 0; s[len]; len++) ;

in real code.