How can we find length of a string without the help of length method of string

Question

How can we find length of a string without the help of length method of string in C# ?

Vulpes · Answer

Here's a rather crude way to do it: using System; class Test { static void Main() { string s = "Shubham"; int length = 0; try { char c; while(true) { c = s[length]; length++; } } catch(IndexOutOfRangeException) { } Console.WriteLine("The length of '{0}' is {1}", s, length); Console.ReadKey(); } } A more elegant way would be to use pointers but, as you wouldn't even be asking the question if you knew about these, then I won't elaborate further.

Vulpes · Answer

Sure, here it is: using System; class Test { unsafe static void Main() { string s = "Shubham"; int length = 0; fixed(char* ps = s) { char* pc = ps; while(*pc++ != '\0') length++; } Console.WriteLine("The length of '{0}' is {1}", s, length); Console.ReadKey(); } } You'll need to compile with the /unsafe switch. This works because, although you're not normally aware of it, all strings in .NET are stored in memory with a terminating null character '\0'. So, all you need to do is to keep incrementing the pointer until the null character is reached. Notice though that, if the string actually contains a null character, then this approach will give an answer which is too small. The 'crude' method doesn't suffer from this problem.

Shubham Srivastava · Answer

Hi Vulpes, Give me the second way to get the length of string using pointer.

How can we find length of a string without the help of length method of string

Answers (3)