How to determine a character within a string in c++

Question

I have a variable named "String" that may have values like the following ones:

const char* String = "/v1/AUTH_abb52a71-fc76-489b-b56b-732b66bf50b1/test/DSC_0188.JPG";

or

const char* String = "/auth/v1.0";

or

const char* String = "/v2/AUTH_abb52a71-fc76-489b-b56b-732b66bf50b1/images?limit=1000&delimiter=/&format=xml";

Now I want to make sure whether or not "String" has the character 'v1'. Checking this has to be precise. I tried with strchr, but it's not quite accurate as it doesn't take 'v1' as one character, it rather takes 'v' and '1' as two separate characters. Moreover I can't use namepace std and library string, I can only use "string.h". Within these limitations how can I accurately check whether the variable "String" has a character 'v1'?

Thank you.

Answer 1

I want to make sure whether or not "String" has the character 'v1'

I can only use "string.h"

Then you probably want strstr . Also v1 is not a character, it's a string.

---

Side note: why use cstring in C++ ? What kind of teacher is still calling it string.h ?!

Answer 2

v1 is not character according to any alphabet. This is a proper string "v1" and as @cnicutar mentioned the c way to search for string in string is to use strstr . It is quite easy to use and runs KMP which is also very fast (though for the kind of your string it is not that crucial).

I would advise you to:

• always name your variables starting small-caps (ie String -> my_string )
• declare your string as const char[] , no need to interfere with pointers, when you can avoid them. Declaring this as pointer might confuse you, that you dynamically allocated the memory for the string.