Use bracket notation to find the last character in the lastName variable.
If you want help, you need to give challenge link and your code.
Next time, to make it easy, If you have a question about a specific challenge as it relates to your written code for that challenge, just click the Ask for Help button located on the challenge. It will create a new topic with all code you have written and include a link to the challenge also. You will still be able to ask any questions in the post before submitting it to the forum.
Thank you.