"*stringPtr++"

Why are you dereferencing the pointer in the for loop when you want just to increment it?

Tests now fail this solution. I think it remains visible because it has upvotes.

This function incorrectly returns True for these characters between 'Z' and 'a':

[\]^_`

that's not true. stringPtr is initialized to the adress of string...

Fixed.

Your code is wrong. Not a kata issue, test it with (14, 52), it returns 49 and 49 is not a prime number.

Read this: https://www.codewars.com/kata/58dff747ca6895f1230000d1/discuss#5a225ec08f27f218480000a3

No idea if it was added after your post, but:

The highest and lowest numbers are not included.

i ran all tests in an ide and they all were correct and when i test it here every single one of them failed :(

expected 49 got 47 tf.

I think you should state something along the fact that the interval is open, not closed. That through me off because my implementation was including the endpoints of the interval, not realizing that the interval was open.

There may be an exception !!! stringPtr contains a randomized value. It may or may not work!

Unpublishing as a duplicate of https://www.codewars.com/kata/55acfc59c3c23d230f00006d/

Duplicate of all the other prime-testing katas.

Duplicate issue.